public OvalTimeDifferenceBuilder WithTimeDifference()
 {
     this.timeDifferenceBuilder = new OvalTimeDifferenceBuilder(this);
     return this.timeDifferenceBuilder;
 }
 public OvalTimeDifferenceBuilder WithTimeDifference()
 {
     this.timeDifferenceBuilder = new OvalTimeDifferenceBuilder(this);
     return(this.timeDifferenceBuilder);
 }