Form_Capabilities::map_meta_cap( array $caps, string $cap, int $user_id, array $args )

	protected function map_meta_cap( $caps, $cap, $user_id, $args ) {
		if ( empty( $this->capability_mappings ) ) {
			return $caps;
		}

		if ( ! isset( $this->capability_mappings[ $cap ] ) ) {
			if ( ! isset( $caps[0] ) || ! isset( $this->capability_mappings[ $caps[0] ] ) ) {
				return $caps;
			}

			$cap = $caps[0];
		}

		$user_id = absint( $user_id );

		if ( is_callable( $this->capability_mappings[ $cap ] ) ) {
			$mapped_cap = call_user_func( $this->capability_mappings[ $cap ], $user_id, $args );
		} else {
			$mapped_cap = $this->capability_mappings[ $cap ];
		}

		$caps = array( $mapped_cap );

		return $this->map_meta_cap( $caps, $mapped_cap, $user_id, $args );
	}