public function errors($field = null, $value = null) {
		if ($field === false) {
			return ($this->_errors = []);
		}
		if ($field === null) {
			return $this->_errors;
		}
		if (is_array($field)) {
			return ($this->_errors = array_merge_recursive($this->_errors, $field));
		}
		if ($value === null && isset($this->_errors[$field])) {
			return $this->_errors[$field];
		}
		if ($value !== null) {
			if (array_key_exists($field, $this->_errors)) {
				$current = $this->_errors[$field];
				return ($this->_errors[$field] = array_merge((array) $current, (array) $value));
			}
			return ($this->_errors[$field] = $value);
		}
		return $value;
	}