Added docstring and defaults to resolve_multi().

- Added docstring to ``resolve_multi()``.
- Added defaults for ``interpreters`` and ``platforms`` params if
  nothing is specified.

pex/resolver.py

@@ -354,7 +354,23 @@ def resolve_multi(requirements,
                   precedence=None,
                   cache=None,
                   cache_ttl=None):
-
+
+  """Produce all distributions needed to (recursively) meet `requirements` for multiple
+  interpreters and/or platforms.
+
+  :keyword interpreters: (optional) An iterable of :class:`PythonInterpreter` objects to use
+    for building distributions and for testing distribution compatibility.
+  :keyword platforms: (optional) An iterable of PEP425-compatible platform strings to use for
+    filtering compatible distributions.  If unspecified, the current platform is used, as
+    determined by `Platform.current()`.
+
+  This method is just a wrapper around the :func:`resolver` method for resolving requirements
+  for multiple interpreters and/or platforms.
+  """
+
+  platforms = platforms or [Platform.current()]
+  interpreters = interpreters or [PythonInterpreter.get()]
+
   resolveds = list()
   for platform in platforms:
     for interpreter in interpreters: