code: def get_parameter_negative_warning(model_type, model_params, parameter):
      
      warnings = []
      if model_params.get(parameter, 0) < 0:
          warnings.append(
              EEMeterWarning(
                  qualified_name=(
                      "eemeter.caltrack_daily.{model_type}.{parameter}_negative".format(
                          model_type=model_type, parameter=parameter
                      )
                  ),
                  description=(
                      "Model fit {parameter} parameter is negative. Candidate model rejected.".format(
                          parameter=parameter
                      )
                  ),
                  data=model_params,
              )
          )
      return warnings
docs: Return an empty list or a single warning wrapped in a list indicating
      whether model parameter is negative.
  
      Parameters
      ----------
      model_type : :any:`str`
          Model type (e.g., ``'cdd_hdd'``).
      model_params : :any:`dict`
          Parameters as stored in :any:`eemeter.CalTRACKUsagePerDayCandidateModel.model_params`.
      parameter : :any:`str`
          The name of the parameter, e.g., ``'intercept'``.
  
      Returns
      -------
      warnings : :any:`list` of :any:`eemeter.EEMeterWarning`
          Empty list or list of single warning.