code: def params():
      """Return a lmfit.Parameters class with initial values."""
      pars = Parameters()
      pars.add_many(
          ("a1", 4),
          ("b", -20.0),
          ("c1", 3),
          ("a", 10.0),
          ("a2", 5),
          ("b10", 6),
          ("d", None),
          ("b01", 8),
          ("e", 9),
          ("aa1", 10),
      )
      return pars
  
imports: import numpy
  import pytest
  import lmfit
  from lmfit import Minimizer, Parameters, ci_report, conf_interval, fit_report, report_ci, report_fit
  from lmfit.lineshapes import gaussian
  from lmfit.models import GaussianModel
  from lmfit.printfuncs import alphanumeric_sort, correl_table, fitreport_html_table, getfloat_attr, gformat
label_desc: Use image node_id 1 for calling a global function with example usage: params() and returns: pars