human
Here's a good function header given the following:
I wrote the below code

    issues = {}
    if is_pyflakes_available():
        import pyflakes.api
        import pyflakes.reporter
        class Reporter(pyflakes.reporter.Reporter, ):
            def __init__(self):
                self._ignored_issues = {}
                for line in CONFIG['pyflakes.ignore']:
                    (path, issue) = line.split('=>')
                    self._ignored_issues.setdefault(path.strip(), []).append(issue.strip())
            def unexpectedError(self, filename, msg):
                self._register_issue(filename, None, msg, None)
            def syntaxError(self, filename, msg, lineno, offset, text):
                self._register_issue(filename, lineno, msg, text)
            def flake(self, msg):
                self._register_issue(msg.filename, msg.lineno, (msg.message % msg.message_args), None)
            def _is_ignored(self, path, issue):
                for (ignored_path, ignored_issues) in self._ignored_issues.items():
                    if (path.endswith(ignored_path) and (issue in ignored_issues)):
                        return True
                return False
            def _register_issue(self, path, line_number, issue, line):
                if (not self._is_ignored(path, issue)):
                    if (path and line_number and (not line)):
                        line = linecache.getline(path, line_number)
                    issues.setdefault(path, []).append(Issue(line_number, issue, line))
        reporter = Reporter()
        for path in _python_files(paths):
            pyflakes.api.checkPath(path, reporter)
    return issues

What's a good function header?
assistant
#Here's a good function header.

def pyflakes_issues(paths):