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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 convert_schemas(d, definitions=None):
 """ Convert Marshmallow schemas to dict definitions Also updates the optional definitions argument with any definitions entries contained within the schema. """

    if Schema is None:
        raise RuntimeError('Please install marshmallow and apispec')

    if definitions is None:
        definitions = {}
    definitions.update(d.get('definitions', {}))

    new = {}
    for k, v in d.items():
        if isinstance(v, dict):
            v = convert_schemas(v, definitions)
        if isinstance(v, (list, tuple)):
            new_v = []
            for item in v:
                if isinstance(item, dict):
                    new_v.append(convert_schemas(item, definitions))
                else:
                    new_v.append(item)
            v = new_v
        if inspect.isclass(v) and issubclass(v, Schema):
            definitions[v.__name__] = schema2jsonschema(v)
            ref = {
                "$ref": "#/definitions/{0}".format(v.__name__)
            }
            if k == 'parameters':
                new[k] = schema2parameters(v)
                new[k][0]['schema'] = ref
            else:
                new[k] = ref
        else:
            new[k] = v

    # This key is not permitted anywhere except the very top level.
    if 'definitions' in new:
        del new['definitions']

    return new