getDependencies( type ) {

		let dependencies = this.cache.get( type );

		if ( ! dependencies ) {

			const parser = this;
			const defs = this.json[ type + ( type === 'mesh' ? 'es' : 's' ) ] || [];

			dependencies = Promise.all( defs.map( function ( def, index ) {

				return parser.getDependency( type, index );

			} ) );

			this.cache.add( type, dependencies );

		}

		return dependencies;

	}
Requests all dependencies of the specified type asynchronously, with caching.

@private
@param {string} type
@return {Promise<Array<Object>>}