trial() {
            if (typeof this.timeline_parameters == "undefined") {
                // returns a clone of the trial_parameters to
                // protect functions.
                return deepCopy(this.trial_parameters);
            }
            else {
                if (this.progress.current_location >= this.timeline_parameters.timeline.length) {
                    return null;
                }
                else {
                    return this.timeline_parameters.timeline[this.progress.current_location].trial();
                }
            }
        }
// otherwise, recursively find the next trial in the child timeline.

otherwise, recursively find the next trial in the child timeline.
otherwise recursively find the next trial in the child timeline .
trial() {
            if (typeof this.timeline_parameters == "undefined") {
                return deepCopy(this.trial_parameters);
            }
            else {
                if (this.progress.current_location >= this.timeline_parameters.timeline.length) {
                    return null;
                }
                else {
                    return this.timeline_parameters.timeline[this.progress.current_location].trial();
                }
            }
        }
trial ( ) { if ( typeof this . timeline_parameters == "undefined" ) { return deepCopy ( this . trial_parameters ) ; } else { if ( this . progress . current_location >= this . timeline_parameters . timeline . length ) { return null ; } else { return this . timeline_parameters . timeline [ this . progress . current_location ] . trial ( ) ; } } }
otherwise, recursively find the next trial in the child timeline.
otherwise recursively find the next trial in the child timeline .
// returns a clone of the trial_parameters to
 // protect functions.
