def head(self, n=6):
        """
        Returns first n values of your column as a DataFrame. This is executing:
            SELECT
                <name_of_the_column>
            FROM
                <name_of_the_table>
            LIMIT <n>

        Parameters
        ----------
        n: int
            number of rows to return

        Examples
        --------
        >>> from db import DemoDB
        >>> db = DemoDB()
        >>> db.tables.Customer.City.head()
        0    Sao Jose dos Campos
        1              Stuttgart
        2               Montreal
        3                   Oslo
        4                 Prague
        5                 Prague
        Name: City, dtype: object
        >>> db.tables.Customer.City.head(2)
        0    Sao Jose dos Campos
        1              Stuttgart
        Name: City, dtype: object
        """
        q = self._query_templates['column']['head'].format(column=self.name, schema=self.schema,
                                                           table=self.table, n=n)
        return pd.read_sql(q, self._con)[self.name]