def get_unitless_standard_names():
global _UNITLESS_DB<EOL>if _UNITLESS_DB is None:<EOL><INDENT>with open(resource_filename('<STR_LIT>', '<STR_LIT>'), '<STR_LIT:r>') as f:<EOL><INDENT>_UNITLESS_DB = json.load(f)<EOL><DEDENT><DEDENT>return _UNITLESS_DB<EOL>
Returns a list of valid standard_names that are allowed to be unitless