Problem

-- is it possible to override ISA fields a DML map ?

-- ex : override X12OverrideEnveloper.Interchange.ISA_I12_Generator

Resolution

* it is not possible to override ISA elements

* it is not possible in DML to override complex structure of some attributes : attributes that have other records as children. The X12 enveloper attribute is one of them, and it won't work

* you need to achieve it in an MBC : declare a variable of the X12.OverrideEnveloper record, set the needed fields for it, then serialize it and setAttribute on it