protected function length($length, $propagate = true)
	{
		$this->length = $this->intCast($length ?: $this->length);
		return $this->propagateMutation('length', $propagate);
	}
protected function length($length, $propagate = true)
	{
		$this->length = $this->intCast($length ?: $this->length);
		return $this->propagateMutation('length', $propagate);
	}
protected function length ( $ length , $ propagate = true ) { $ this -> length = $ this -> intCast ( $ length ? : $ this -> length ) ; return $ this -> propagateMutation ( 'length' , $ propagate ) ; }
Sets the length of keys to be generated by the generator.

@param numeric $length
@param bool $propagate
@return $this

@throws \InvalidArgumentException
Sets the length of keys to be generated by the generator .