Field::sanitize()

	public function sanitize() {
		if ( true === $this->sanitized ) {
			return $this->sanitized_value;
		}

		if ( ! empty( $this->sanitize_cb ) ) {
			$unsafe_value     = $this->unsafe_value();
			$sanitize_applied = false;

			foreach ( (array) $this->sanitize_cb as $sanitize ) {
				// Callback for sanitizing field type.
				$cb = 'sanitize_' . trim( $sanitize );

				if ( method_exists( 'AnsPress\Form\Validate', $cb ) ) {
					$sanitized_val = call_user_func_array( 'AnsPress\Form\Validate::' . $cb, $this->sanitize_cb_args( $unsafe_value ) );

					// If callback is null then do not apply.
					if ( null !== $sanitized_val ) {
						$sanitize_applied = true;
						$unsafe_value     = $sanitized_val;
					}
				}
			}

			$this->sanitized = true;
			if ( null !== $unsafe_value && true === $sanitize_applied ) {
				$this->sanitized_value = $unsafe_value;
			}
		}

		return $this->sanitized_value;
	}