docs: def get_requirements(
              self, install=True, extras=True, setup=False, tests=False):
          """Get package requirements."""
          requires = []
          if install:
              requires.extend(parse_requirements(
                  self.keywords.get('install_requires', ()),
              ))
          if extras:
              for r in self.keywords.get('extras_require', {}).values():
                  requires.extend(parse_requirements(r))
          if setup:
              requires.extend(parse_requirements(
                  self.keywords.get('setup_requires', ()),
              ))
          if tests:
              requires.extend(parse_requirements(
                  self.keywords.get('tests_require', ()),
              ))
          return requires