code: def set_output_type(fsl_output_type):
      prev_output_type = os.environ.get("FSLOUTPUTTYPE", None)
  
      if fsl_output_type is not None:
          os.environ["FSLOUTPUTTYPE"] = fsl_output_type
      elif "FSLOUTPUTTYPE" in os.environ:
          del os.environ["FSLOUTPUTTYPE"]
  
      FSLCommand.set_default_output_type(Info.output_type())
      return prev_output_type
  
file_path: nipype/nipype/testing/fixtures.py
imports: import os
  import pytest
  import numpy
  import nibabel
  from nipype.utils.filemanip import ensure_list
  from nipype.interfaces.fsl import Info
  from nipype.interfaces.fsl.base import FSLCommand
label_desc: Use image node_id 7 for calling a global function with example usage: set_output_type(fsl_output_type) and returns: prev_output_type