FhirTime constructor
      
      FhirTime(
    
    
- dynamic inValue
Implementation
factory FhirTime(dynamic inValue) => inValue is String &&
        RegExp(r'^([01][0-9]|2[0-3])(:([0-5][0-9])(:([0-5][0-9]|60)(\.[0-9]+)?)?)?$')
            .hasMatch(inValue)
    ? FhirTime._(inValue, inValue, true)
    : FhirTime._(inValue.toString(), null, false);