When generating API stubs with the scaffold utility using, e.g., `python -m localstack.aws.scaffold sns`,
the scaffold creates method names from operation names, which are ugly when acronyms (subsequent uppercase characters that belong together).

Example:
`CreateSMSSandboxPhoneNumber` -> `create_s_m_s_sandbox_phone_number`

it would be nicer to have `create_sms_sandbox_phone_number`

This is a limitation of this method: https://github.com/localstack/localstack/blob/1888e66b85d7e6a8ee457bc7a732984fcf7aa830/localstack/utils/common.py#L978-L979
)
                    for instream, outstream in streams:
                        if not instream:
                            continue
                        for line in iter(instream.readline, None):
                            
                            
                            if line in [None, "", b""]:
                                break
                            if not (line and line.strip()) and self.is_killed():
                                break
                            line = convert_line(line)
                            if filter_line(line):
                                continue
                            if self.log_listener:
                                self.log_listener(line, stream=instream)
                            if self.outfile not in [None, os.devnull]:
                                outstream.write(line)
                                outstream.flush()
                if self.process:
                    self.process.wait()
            else:
                self.process.communicate()
        except Exception as e:
            self.result_future.set_exception(e)
            if self.process and not self.quiet:
                LOG.warning('Shell command error "%s": %s', e, self.cmd)
        if self.process and not self.quiet and self.process.returncode != 0:
            LOG.warning('Shell command exit code "%s": %s', self.process.returncode, self.cmd)
    def is_killed(self):