usage: chaste_codegen [-h] [--version] [--normal] [--cvode]
                      [--cvode-data-clamp] [--backward-euler] [--rush-larsen]
                      [--grl1] [--grl2] [-j] [-o OUTFILE]
                      [--output-dir OUTPUT_DIR] [--show-outputs] [-c CLS_NAME]
                      [-q] [-y] [--opt] [-m]
                      cellml_file
chaste_codegen: error: the following arguments are required: cellml_file
