underscored() публичный метод

Underscores are inserted before uppercase characters (with the exception of the first character of the string), and in place of spaces as well as dashes.
public underscored ( ) : Stringy
Результат Stringy Object with an underscored $str
 /**
  * Guesses possible raw data keys from a constructor parameter name.
  *
  * @param \ReflectionParameter $parameter The parameter to guess keys for
  *
  * @return array
  */
 private function getPossibleParameterKeys(\ReflectionParameter $parameter)
 {
     $parameterString = new Stringy($parameter->getName());
     return array((string) $parameterString->underscored(), (string) $parameterString->regexReplace('([a-z]+)([0-9]+)', '\\1_\\2'), $parameter->getName());
 }