def check_docstring_missing(self, definition, docstring):
        """D10{0,1,2,3}: Public definitions should have docstrings.

        All modules should normally have docstrings.  [...] all functions and
        classes exported by a module should also have docstrings. Public
        methods (including the __init__ constructor) should also have
        docstrings.

        Note: Public (exported) definitions are either those with names listed
              in __all__ variable (if present), or those that do not start
              with a single underscore.

        """
        if (not docstring and definition.is_public or
                docstring and is_blank(ast.literal_eval(docstring))):
            codes = {Module: violations.D100,
                     Class: violations.D101,
                     NestedClass: violations.D106,
                     Method: (lambda: violations.D105() if definition.is_magic
                              else (violations.D107() if definition.is_init
                              else violations.D102())),
                     Function: violations.D103,
                     NestedFunction: violations.D103,
                     Package: violations.D104}
            return codes[type(definition)]()
D10{0,1,2,3}: Public definitions should have docstrings.

        All modules should normally have docstrings.  [...] all functions and
        classes exported by a module should also have docstrings. Public
        methods (including the __init__ constructor) should also have
        docstrings.

        Note: Public (exported) definitions are either those with names listed
              in __all__ variable (if present), or those that do not start
              with a single underscore.