WP_User::has_cap( string $cap )

	public function has_cap( $cap ) {
		if ( is_numeric( $cap ) ) {
			_deprecated_argument( __FUNCTION__, 'WP-2.0.0', __( 'Usage of user levels is deprecated. Use capabilities instead.' ) );
			$cap = $this->translate_level_to_cap( $cap );
		}

		$args = array_slice( func_get_args(), 1 );
		$args = array_merge( array( $cap, $this->ID ), $args );
		$caps = call_user_func_array( 'map_meta_cap', $args );

		// Multisite super admin has all caps by definition, Unless specifically denied.
		if ( is_multisite() && is_super_admin( $this->ID ) ) {
			if ( in_array('do_not_allow', $caps) )
				return false;
			return true;
		}

		/**
		 * Dynamically filter a user's capabilities.
		 *
		 * @since WP-2.0.0
		 * @since WP-3.7.0 Added the user object.
		 *
		 * @param array   $allcaps An array of all the user's capabilities.
		 * @param array   $caps    Actual capabilities for meta capability.
		 * @param array   $args    Optional parameters passed to has_cap(), typically object ID.
		 * @param WP_User $user    The user object.
		 */
		$capabilities = apply_filters( 'user_has_cap', $this->allcaps, $caps, $args, $this );

		// Everyone is allowed to exist.
		$capabilities['exist'] = true;

		// Nobody is allowed to do things they are not allowed to do.
		unset( $capabilities['do_not_allow'] );

		// Must have ALL requested caps.
		foreach ( (array) $caps as $cap ) {
			if ( empty( $capabilities[ $cap ] ) )
				return false;
		}

		return true;
	}