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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 load_table(self, table):
 """Loads a table. Returns None if the table does not already exist in db """

        table = self._valid_table_name(table)
        schema, table = self.parse_table_name(table)
        if not schema:
            schema = self.schema
            tables = self.tables
        else:
            tables = self.tables_in_schema(schema)
        if table in tables:
            return Table(self, schema, table)
        else:
            return None