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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_argument_values( arg_defs, # type: Union[Dict[str, GraphQLArgument], Dict] arg_asts, # type: Optional[List[Argument]] variables=None, # type: Optional[Dict[str, Union[List, Dict, int, float, bool, str, None]]] ):
 """Prepares an object map of argument values given a list of argument definitions and list of argument AST nodes."""

    if not arg_defs:
        return {}

    if arg_asts:
        arg_ast_map = {
            arg.name.value: arg for arg in arg_asts
        }  # type: Dict[str, Argument]
    else:
        arg_ast_map = {}

    result = {}
    for name, arg_def in arg_defs.items():
        arg_type = arg_def.type
        arg_ast = arg_ast_map.get(name)
        if name not in arg_ast_map:
            if arg_def.default_value is not None:
                result[arg_def.out_name or name] = arg_def.default_value
                continue
            elif isinstance(arg_type, GraphQLNonNull):
                raise GraphQLError(
                    'Argument "{name}" of required type {arg_type}" was not provided.'.format(
                        name=name, arg_type=arg_type
                    ),
                    arg_asts,
                )
        elif isinstance(arg_ast.value, ast.Variable):  # type: ignore
            variable_name = arg_ast.value.name.value  # type: ignore
            if variables and variable_name in variables:
                result[arg_def.out_name or name] = variables[variable_name]
            elif arg_def.default_value is not None:
                result[arg_def.out_name or name] = arg_def.default_value
            elif isinstance(arg_type, GraphQLNonNull):
                raise GraphQLError(
                    'Argument "{name}" of required type {arg_type}" provided the variable "${variable_name}" which was not provided'.format(
                        name=name, arg_type=arg_type, variable_name=variable_name
                    ),
                    arg_asts,
                )
            continue

        else:
            value = value_from_ast(arg_ast.value, arg_type, variables)  # type: ignore
            if value is None:
                if arg_def.default_value is not None:
                    value = arg_def.default_value
                    result[arg_def.out_name or name] = value
            else:
                # We use out_name as the output name for the
                # dict if exists
                result[arg_def.out_name or name] = value

    return result