<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def prepare(cls, value, length=0, position=0, is_last_data=True):
 """Prepare Lob header. Note that the actual lob data is NOT written here but appended after the parameter block for each row! """

        hstruct = WriteLobHeader.header_struct
        lob_option_dataincluded = WriteLobHeader.LOB_OPTION_DATAINCLUDED if length > 0 else 0
        lob_option_lastdata = WriteLobHeader.LOB_OPTION_LASTDATA if is_last_data else 0
        options = lob_option_dataincluded | lob_option_lastdata
        pfield = hstruct.pack(cls.type_code, options, length, position)
        return pfield