Make it clearer which things are public in pgen

parso/parser.py

@@ -16,7 +16,7 @@ complexity of the ``Parser`` (there's another parser sitting inside
 ``Statement``, which produces ``Array`` and ``Call``).
 """
 from parso import tree
-from parso.pgen2.parse import PgenParser
+from parso.pgen2 import PgenParser
 
 
 class ParserSyntaxError(Exception):

parso/pgen2/__init__.py

@@ -8,3 +8,4 @@
 # Modifications are dual-licensed: MIT and PSF.
 
 from parso.pgen2.generator import generate_grammar
+from parso.pgen2.parse import PgenParser