Fix issue where IntelliJ reports an assertion issue in the SpecimenCompoundsMapper

[MartinWheelerMT]

What

Fix issue with IntelliJ reporting a problem with isEqualTo when comparing the actual in the assertation to the expected valued in the isEqualTo

Why

IntelliJ reports a problem with isEqualTo when comparing the actual in the assertation to the expected valued in the isEqualTo. This is not a java problem but will prevent IntelliJ displaying a yellow waring.

The IntelliJ warning is:

'isEqualTo()' between objects of inconvertible types 'List<RCMRMT030101UKCompoundStatement>' and 'List<String>' 

Type of change

Please delete options that are not relevant.

• Internal change (non-breaking change with no effect on the functionality affecting end users)

Checklist:

• I have performed a self-review of my code
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes