Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like WC_Order_Item often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use WC_Order_Item, and based on these observations, apply Extract Interface, too.
1 | <?php |
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17 | class WC_Order_Item extends WC_Data implements ArrayAccess { |
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18 | |||
19 | /** |
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20 | * Data array, with defaults. |
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21 | * @since 2.7.0 |
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22 | * @var array |
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23 | */ |
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24 | protected $_data = array( |
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25 | 'order_id' => 0, |
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26 | 'order_item_id' => 0, |
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27 | 'name' => '', |
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28 | 'type' => '', |
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29 | ); |
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30 | |||
31 | /** |
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32 | * Stores meta in cache for future reads. |
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33 | * A group must be set to to enable caching. |
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34 | * @var string |
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35 | */ |
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36 | protected $_cache_group = 'order_itemmeta'; |
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37 | |||
38 | /** |
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39 | * Meta type. This should match up with |
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40 | * the types avaiable at https://codex.wordpress.org/Function_Reference/add_metadata. |
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41 | * WP defines 'post', 'user', 'comment', and 'term'. |
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42 | */ |
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43 | protected $_meta_type = 'order_item'; |
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44 | |||
45 | /** |
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46 | * Constructor. |
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47 | * @param int|object|array $order_item ID to load from the DB (optional) or already queried data. |
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48 | */ |
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49 | public function __construct( $item = 0 ) { |
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60 | |||
61 | /** |
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62 | * Set all data based on input array. |
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63 | * @param array $data |
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64 | * @access private |
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65 | */ |
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66 | public function set_all( $data ) { |
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75 | |||
76 | /** |
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77 | * Type checking |
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78 | * @param string|array $Type |
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79 | * @return boolean |
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80 | */ |
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81 | public function is_type( $type ) { |
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84 | |||
85 | /** |
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86 | * Get qty. |
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87 | * @return int |
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88 | */ |
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89 | public function get_qty() { |
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92 | |||
93 | /* |
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94 | |-------------------------------------------------------------------------- |
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95 | | Getters |
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96 | |-------------------------------------------------------------------------- |
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97 | */ |
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98 | |||
99 | /** |
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100 | * Get order item ID. |
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101 | * @return int |
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102 | */ |
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103 | public function get_id() { |
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106 | |||
107 | /** |
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108 | * Get order ID this meta belongs to. |
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109 | * @return int |
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110 | */ |
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111 | public function get_order_id() { |
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114 | |||
115 | /** |
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116 | * Get order item ID this meta belongs to. |
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117 | * @return int |
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118 | */ |
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119 | public function get_order_item_id() { |
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122 | |||
123 | /** |
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124 | * Get order item name. |
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125 | * @return string |
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126 | */ |
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127 | public function get_name() { |
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130 | |||
131 | /** |
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132 | * Get order item type. |
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133 | * @return string |
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134 | */ |
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135 | public function get_type() { |
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138 | |||
139 | /* |
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140 | |-------------------------------------------------------------------------- |
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141 | | Setters |
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142 | |-------------------------------------------------------------------------- |
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143 | */ |
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144 | |||
145 | /** |
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146 | * Set ID |
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147 | * @param int $value |
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148 | */ |
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149 | public function set_id( $value ) { |
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152 | |||
153 | /** |
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154 | * Set order ID. |
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155 | * @param int $value |
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156 | */ |
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157 | public function set_order_id( $value ) { |
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160 | |||
161 | /** |
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162 | * Set order item ID. |
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163 | * @param int $value |
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164 | */ |
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165 | public function set_order_item_id( $value ) { |
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168 | |||
169 | /** |
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170 | * Set order item name. |
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171 | * @param string $value |
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172 | */ |
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173 | public function set_name( $value ) { |
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176 | |||
177 | /** |
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178 | * Set order item type. |
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179 | * @param string $value |
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180 | */ |
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181 | public function set_type( $value ) { |
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185 | |||
186 | /* |
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187 | |-------------------------------------------------------------------------- |
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188 | | CRUD methods |
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189 | |-------------------------------------------------------------------------- |
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190 | | |
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191 | | Methods which create, read, update and delete data from the database. |
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192 | | |
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193 | */ |
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194 | |||
195 | /** |
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196 | * Insert data into the database. |
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197 | * @since 2.7.0 |
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198 | */ |
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199 | View Code Duplication | public function create() { |
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211 | |||
212 | /** |
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213 | * Update data in the database. |
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214 | * @since 2.7.0 |
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215 | */ |
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216 | View Code Duplication | public function update() { |
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227 | |||
228 | /** |
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229 | * Read from the database. |
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230 | * @since 2.7.0 |
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231 | * @param int|object $item ID of object to read, or already queried object. |
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232 | */ |
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233 | public function read( $item ) { |
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252 | |||
253 | /** |
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254 | * Save data to the database. |
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255 | * @since 2.7.0 |
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256 | * @return int Item ID |
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257 | */ |
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258 | public function save() { |
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268 | |||
269 | /** |
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270 | * Delete data from the database. |
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271 | * @since 2.7.0 |
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272 | */ |
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273 | public function delete() { |
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282 | |||
283 | /* |
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284 | |-------------------------------------------------------------------------- |
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285 | | Meta Data Handling |
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286 | |-------------------------------------------------------------------------- |
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287 | */ |
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288 | |||
289 | /** |
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290 | * Expands things like term slugs before return. |
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291 | * @param string $hideprefix (default: _) |
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292 | * @return array |
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293 | */ |
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294 | public function get_formatted_meta_data( $hideprefix = '_' ) { |
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324 | |||
325 | /* |
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326 | |-------------------------------------------------------------------------- |
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327 | | Array Access Methods |
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328 | |-------------------------------------------------------------------------- |
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329 | | |
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330 | | For backwards compat with legacy arrays. |
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331 | | |
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332 | */ |
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333 | |||
334 | /** |
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335 | * offsetSet for ArrayAccess |
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336 | * @param string $offset |
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337 | * @param mixed $value |
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338 | */ |
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339 | public function offsetSet( $offset, $value ) { |
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353 | |||
354 | /** |
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355 | * offsetUnset for ArrayAccess |
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356 | * @param string $offset |
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357 | */ |
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358 | public function offsetUnset( $offset ) { |
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370 | |||
371 | /** |
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372 | * offsetExists for ArrayAccess |
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373 | * @param string $offset |
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374 | * @return bool |
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375 | */ |
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376 | public function offsetExists( $offset ) { |
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382 | |||
383 | /** |
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384 | * offsetGet for ArrayAccess |
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385 | * @param string $offset |
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386 | * @return mixed |
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387 | */ |
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388 | public function offsetGet( $offset ) { |
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412 | } |
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413 |
This check looks for PHPDoc comments describing methods or function parameters that do not exist on the corresponding method or function.
Consider the following example. The parameter
$italy
is not defined by the methodfinale(...)
.The most likely cause is that the parameter was removed, but the annotation was not.