code: public static function setPost($strKey, $varValue)
  	{
  		$strKey = static::cleanKey($strKey);
  
  		unset(static::$arrCache['postEncoded'][$strKey]);
  		unset(static::$arrCache['postDecoded'][$strKey]);
  		unset(static::$arrCache['postHtmlEncoded'][$strKey]);
  		unset(static::$arrCache['postHtmlDecoded'][$strKey]);
  		unset(static::$arrCache['postRaw'][$strKey]);
  		unset(static::$arrCache['postUnsafeRaw'][$strKey]);
  
  		if ($varValue === null)
  		{
  			unset($_POST[$strKey]);
  		}
  		else
  		{
  			$_POST[$strKey] = $varValue;
  		}
  	}
docs: Set a $_POST variable
  
  @param string $strKey   The variable name
  @param mixed  $varValue The variable value