code_gen omits docstrings on Python 3.7

[Kodiologist]

$ python -c 'import ast, astor; print(astor.code_gen.to_source(ast.Module(body = [ast.parse("def f():\n \"docstring\"\n 1")])) )'
def f():
    1

$ python -c 'import ast, astor; print(astor.code_gen.to_source(ast.Module(body = [ast.parse("class C:\n \"docstring\"\n 1")])) )'
class C:
    1

$ python -c 'import ast, astor; print(astor.code_gen.to_source(ast.Module(body = [ast.parse("\"hello\"\n1")])))' 
1

[berkerpeksag]

I assume the cause of this is the new node.docstring attribute in 3.7?

[Kodiologist]

That seems like a good bet.