function done( error, files ) {
		var out;
		var i;
		if ( error ) {
			debug( 'Encountered an error: %s', error.message );
			return cb( error );
		}
		debug( 'Building database...' );
		out = {};
		for ( i = 0; i < files.length; i++ ) {
			out[ files[ i ].file ] = files[ i ].data;
		}
		debug( 'Finished building database.' );
		cb( null, out );
	}
Callback invoked upon reading files.

@private
@param {(Error|null)} error - error object
@param {(EmptyArray|ObjectArray)} files - file contents
@returns {void}