code: def _check_lsm_input(self, data_var_map_array):
          
          REQUIRED_HMET_VAR_LIST = ['Prcp', 'Pres', 'Temp', 'Clod',
                                    'RlHm', 'Drad', 'Grad', 'WndS']
  
          # make sure all required variables exist
          given_hmet_var_list = []
          for gssha_data_var, lsm_data_var in data_var_map_array:
              gssha_data_hmet_name = self.netcdf_attributes[gssha_data_var]['hmet_name']
  
              if gssha_data_hmet_name in given_hmet_var_list:
                  raise ValueError("Duplicate parameter for HMET variable {0}"
                                   .format(gssha_data_hmet_name))
              else:
                  given_hmet_var_list.append(gssha_data_hmet_name)
  
          for REQUIRED_HMET_VAR in REQUIRED_HMET_VAR_LIST:
              if REQUIRED_HMET_VAR not in given_hmet_var_list:
                  raise ValueError("ERROR: HMET param is required to continue "
                                   "{0} ...".format(REQUIRED_HMET_VAR))
docs: This function checks the input var map array
          to ensure the required input variables exist