code: def unpack_source_dists(self, arguments, use_wheels=False):
          
          unpack_timer = Timer()
          logger.info("Unpacking distribution(s) ..")
          with PatchedAttribute(pip_install_module, 'PackageFinder', CustomPackageFinder):
              requirements = self.get_pip_requirement_set(arguments, use_remote_index=False, use_wheels=use_wheels)
              logger.info("Finished unpacking %s in %s.", pluralize(len(requirements), "distribution"), unpack_timer)
              return requirements
docs: Find and unpack local source distributions and discover their metadata.
  
          :param arguments: The command line arguments to ``pip install ...`` (a
                            list of strings).
          :param use_wheels: Whether pip and pip-accel are allowed to use wheels_
                             (:data:`False` by default for backwards compatibility
                             with callers that use pip-accel as a Python API).
          :returns: A list of :class:`pip_accel.req.Requirement` objects.
          :raises: Any exceptions raised by pip, for example
                   :exc:`pip.exceptions.DistributionNotFound` when not all
                   requirements can be satisfied.
  
          This function checks whether there are local source distributions
          available for all requirements, unpacks the source distribution
          archives and finds the names and versions of the requirements. By using
          the ``pip install --download`` command we avoid reimplementing the
          following pip features:
  
          - Parsing of ``requirements.txt`` (including recursive parsing).
          - Resolution of possibly conflicting pinned requirements.
          - Unpacking source distributions in multiple formats.
          - Finding the name & version of a given source distribution.