code: def build_usage():
      modelnames = []
      ms = ""
      for d in sorted(Models.keys()):
          ms = ms + f" {d} "
          if len(ms) > 55:
              modelnames.append(ms)
              ms = "    "
      modelnames.append(ms)
      modelnames = "\n".join(modelnames)
  
      usage = f"""
   === Test Fit to NIST StRD Models ===
  
  usage:
  ------
      python fit_NIST.py [options] Model Start
  
  where Start is one of 'start1','start2' or 'cert', for different
  starting values, and Model is one of
  
      {modelnames}
  
  if Model = 'all', all models and starting values will be run.
  
  options:
  --------
    -m  name of fitting method.  One of:
            leastsq, nelder, powell, lbfgsb, bfgs,
            tnc, cobyla, slsqp, cg, newton-cg
        leastsq (Levenberg-Marquardt) is the default
  """
      return usage
  
imports: import math
  from optparse import OptionParser
  from numpy.testing import assert_allclose
  from lmfit import Parameters, minimize
  from .NISTModels import Models, ReadNistData
label_desc: Use image node_id 4 for calling a global function with example usage: build_usage() and returns: usage