public VisionPrescription setDateWritten(Date value) { 
      if (value == null)
        this.dateWritten = null;
      else {
        if (this.dateWritten == null)
          this.dateWritten = new DateTimeType();
        this.dateWritten.setValue(value);
      }
      return this;
    }
public VisionPrescription setDateWritten ( Date value ) { if ( value == null ) this . dateWritten = null ; else { if ( this . dateWritten == null ) this . dateWritten = new DateTimeType ( ) ; this . dateWritten . setValue ( value ) ; } return this ; }
@param value The date (and perhaps time) when the prescription was written.