public function get_source() {
		if ( is_callable( $this->source ) ) {
			return call_user_func_array( $this->source, [$this->slug] );
		}

		if ( is_string( $this->source ) && strpos( $this->source, '#' ) !== false ) {
			$source = explode( '#', $this->source );

			if ( empty( $source[0] ) || empty( $source[1] ) ) {
				return $this->source;
			}

			$source[0] = new $source[0]();

			if ( method_exists( $source[0], $source[1] ) ) {
				return call_user_func_array( $source, [$this->slug] );
			}

			return;
		}

		return $this->source;
	}