Is there a way to only pass certain fields from a `record` type to a step? As opposed to the whole record object?

This is my best guess, but I was wondering if there was a cleaner way:


    inputs:
      samples:
        type:
          type: array
          items:
            type: record
            fields:
              fastq1: File
              fastq2: File
              SM: string

    steps:
      step_1: 
        in:
          samples: samples
        out: [bams]

      step_2:
        in:
          bams: step_1/bams
          SM: 
            valueFrom: ${ return inputs.samples.map(function(x) { return x.SM }) }
        out: [changed_bams]

You almost have it: 

    steps:
      step_2:
        in:
          SM:
            source: samples
            valueFrom: ${ return self.map(function(x) { return x.SM })
