How to use the yay.ast.PythonClass function in yay

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
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# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from yay import ast


class GraphExternalAction(ast.PythonClass):

    def test(self):
        pass

    def destroy(self):
        pass

    def _resolve(self):
        # FIXME: There is a nicer way to do this without resolve, but more yay
        # refactoring required
        root = self.root
        if self not in root.actors:
            root.actors.append(self)
        return super(GraphExternalAction, self)._resolve()

elif self.type == 'boolean':
            if isinstance(value, type(True)):
                # might already be boolean
                return value
            if value.lower() in ('no', '0', 'off', 'false'):
                return False
            elif value.lower() in ('yes', '1', 'on', 'true'):
                return True
            raise ArgParseError(
                "Cannot parse boolean from %r for argument %r" % (value, self.name))
        else:
            raise ArgParseError(
                "Don't understand %r as a type for argument %r" % (self.type, self.name))


class YaybuArgv(ast.PythonClass):

    def __init__(self, **args):
        super(YaybuArgv, self).__init__(ast.PythonDict({}))
        self.schema = {}
        self.args = args
        self.anchor = None

    @classmethod
    def from_argv(cls, argv):
        arguments = {}
        for arg in argv:
            name, value = arg.split("=", 1)
            if name in arguments:
                raise ArgParseError(
                    "Duplicate argument %r specified" % (name,))
            arguments[name] = value