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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 schema():
 """Provide schema for shell configuration."""

        return Schema({
            'script': And(Or(type(' '), type(u' ')), len),
            Optional('title', default=''): str,
            Optional('model', default={}): {Optional(And(str, len)): object},
            Optional('env', default={}): {Optional(And(str, len)): And(str, len)},
            Optional('item', default=None): object,
            Optional('dry_run', default=False): bool,
            Optional('debug', default=False): bool,
            Optional('strict', default=False): bool,
            Optional('variables', default={}): {
                Optional(And(Or(type(' '), type(u' ')), len, Regex(r'([a-zA-Z][_a-zA-Z]*)'))):
                    Or(type(' '), type(u' '))
            },
            Optional('temporary_scripts_path', default=''): Or(type(''), type(u'')),
            Optional('internal', default=False): bool
        })