| @@ 3390-3398 (lines=9) @@ | ||
| 3387 | * @return static  | 
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| 3388 | * <p>Object with all characters of $str being lowercase.</p>  | 
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| 3389 | */  | 
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| 3390 | public function toLowerCase($tryToKeepStringLength = false, $lang = null): self  | 
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| 3391 |     { | 
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| 3392 | return static::create(  | 
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| 3393 | $this->utf8::strtolower(  | 
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| 3394 | $this->str,  | 
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| 3395 | $this->encoding,  | 
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| 3396 | false,  | 
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| 3397 | $lang,  | 
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| 3398 | $tryToKeepStringLength  | 
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| 3399 | ),  | 
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| 3400 | $this->encoding  | 
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| 3401 | );  | 
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| @@ 3522-3528 (lines=7) @@ | ||
| 3519 | * @return static  | 
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| 3520 | * <p>Object with all characters of $str being uppercase.</p>  | 
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| 3521 | */  | 
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| 3522 | public function toUpperCase($tryToKeepStringLength = false, $lang = null): self  | 
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| 3523 |     { | 
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| 3524 | return static::create(  | 
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| 3525 | $this->utf8::strtoupper($this->str, $this->encoding, false, $lang, $tryToKeepStringLength),  | 
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| 3526 | $this->encoding  | 
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| 3527 | );  | 
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| 3528 | }  | 
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| 3529 | ||
| 3530 | /**  | 
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| 3531 | * Returns a string with whitespace removed from the start and end of the  | 
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