returns default empty value 
        :param formattype:
        :param buff:
        :param start:
        :param end:

def _empty_value(self, formattype):
        '''
            returns default empty value 
        :param formattype:
        :param buff:
        :param start:
        :param end:
        '''
        if formattype.value.idx <= FormatType.BIN_32.value.idx:  # @UndefinedVariable
            return b''
        elif formattype.value.idx <= FormatType.FIXSTR.value.idx:  # @UndefinedVariable  
            return ''
        elif formattype.value.idx <= FormatType.INT_64.value.idx:  # @UndefinedVariable
            return 0
        elif formattype.value.idx <= FormatType.UINT_64.value.idx:  # @UndefinedVariable
            return 0
        elif(formattype is FormatType.FLOAT_32):
            return float(0)
        elif(formattype is FormatType.FLOAT_64):
            return float(0)