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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_event_items():
 """Schema for event items."""

        return {
            'timestamp': And(int, lambda n: n > 0),
            Optional('information', default={}): {
                Optional(Regex(r'([a-z][_a-z]*)')): object
            }
        }