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:
| 1 | <?php  | 
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| 15 | class Urls { | 
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| 16 | |||
| 17 | const HTTPS_CHECK_OPTION_PREFIX = 'jetpack_sync_https_history_';  | 
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| 18 | const HTTPS_CHECK_HISTORY = 5;  | 
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| 19 | |||
| 20 | /**  | 
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| 21 | * Return URL from option or PHP constant.  | 
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| 22 | *  | 
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| 23 | * @param string $option_name (e.g. 'home').  | 
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| 24 | *  | 
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| 25 | * @return mixed|null URL.  | 
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| 26 | */  | 
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| 27 | 	public static function get_raw_url( $option_name ) { | 
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| 45 | |||
| 46 | /**  | 
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| 47 | * Normalize domains by removing www unless declared in the site's option.  | 
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| 48 | *  | 
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| 49 | * @param string $option Option value from the site.  | 
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| 50 | * @param callable $url_function Function retrieving the URL to normalize.  | 
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| 51 | * @return mixed|string URL.  | 
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| 52 | */  | 
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| 53 | 	public static function normalize_www_in_url( $option, $url_function ) { | 
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| 81 | |||
| 82 | /**  | 
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| 83 | * Return URL with a normalized protocol.  | 
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| 84 | *  | 
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| 85 | * @param callable $callable Function to retrieve URL option.  | 
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| 86 | * @param string $new_value URL Protocol to set URLs to.  | 
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| 87 | * @return string Normalized URL.  | 
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| 88 | */  | 
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| 89 | 	public static function get_protocol_normalized_url( $callable, $new_value ) { | 
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| 113 | |||
| 114 | /**  | 
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| 115 | * Helper function that is used when getting home or siteurl values. Decides  | 
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| 116 | * whether to get the raw or filtered value.  | 
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| 117 | *  | 
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| 118 | * @param string $url_type URL to get, home or siteurl.  | 
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| 119 | * @return string  | 
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| 120 | */  | 
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| 121 | 	public static function get_raw_or_filtered_url( $url_type ) { | 
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| 139 | |||
| 140 | /**  | 
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| 141 | * Return the escaped home_url.  | 
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| 142 | *  | 
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| 143 | * @return string  | 
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| 144 | */  | 
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| 145 | 	public static function home_url() { | 
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| 157 | |||
| 158 | /**  | 
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| 159 | * Return the escaped siteurl.  | 
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| 160 | *  | 
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| 161 | * @return string  | 
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| 162 | */  | 
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| 163 | 	public static function site_url() { | 
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| 175 | |||
| 176 | /**  | 
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| 177 | * Return main site URL with a normalized protocol.  | 
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| 178 | *  | 
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| 179 | * @return string  | 
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| 180 | */  | 
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| 181 | 	public static function main_network_site_url() { | 
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| 184 | |||
| 185 | }  | 
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| 186 | 
This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently.
Both the
$myVarassignment in line 1 and the$higherassignment in line 2 are dead. The first because$myVaris never used and the second because$higheris always overwritten for every possible time line.