@classmethod
def get_converter(cls, in_type, out_type):
    """
        @param::in_type: the input datafram type in string
        @param::out_type: the output datafram type in string
        return the converter class that can perform the dataframe conversion
        """
    for c in cls.__converters__:
        if c.is_capable(in_type, out_type):
            return c
