public ServiceRequest setOccurrence(Type value) { 
      if (value != null && !(value instanceof DateTimeType || value instanceof Period || value instanceof Timing))
        throw new Error("Not the right type for ServiceRequest.occurrence[x]: "+value.fhirType());
      this.occurrence = value;
      return this;
    }
public ServiceRequest setOccurrence ( Type value ) { if ( value != null && ! ( value instanceof DateTimeType || value instanceof Period || value instanceof Timing ) ) throw new Error ( "Not the right type for ServiceRequest.occurrence[x]: " + value . fhirType ( ) ) ; this . occurrence = value ; return this ; }
@param value {@link #occurrence} (The date/time at which the requested service should occur.)