DetailRecord class Indicator FieldNullValue required

[phatbear]

An exception is thrown when reading a file with DetailRecords containing blank Indicators. This is resolved by adding FieldNullValue as per below

[FieldFixedLength(1)]
[FieldConverter(typeof(EnumConverter), typeof(Indicator))]
[FieldNullValue(typeof(Indicator), "0")]
public Indicator Indicator;