def get(self, section: str, option: str, *args: Any, **kwargs: Any) -> str: # type: ignore
        """Get a value, replacing environment variables also.

        The arguments are the same as `ConfigParser.get`, but in the found
        value, ``$WORD`` or ``${WORD}`` are replaced by the value of the
        environment variable ``WORD``.

        Returns the finished value.

        """
        for section_prefix in self.section_prefixes:
            real_section = section_prefix + section
            if super().has_option(real_section, option):
                break
        else:
            raise ConfigError(f"No option {option!r} in section: {section!r}")

        v: str = super().get(real_section, option, *args, **kwargs)
        v = substitute_variables(v, os.environ)
        return v
Get a value, replacing environment variables also.

        The arguments are the same as `ConfigParser.get`, but in the found
        value, ``$WORD`` or ``${WORD}`` are replaced by the value of the
        environment variable ``WORD``.

        Returns the finished value.

        
coverage/config.py