rebased convert on ConvertionError instead of TypeError
Revert "rebased convert on ConvertionError instead of TypeError"

This reverts commit e6498f7e27c26640333acc27d03073e29be2fdee.
fixed abstract metods work
Revert "Revert "rebased convert on ConvertionError instead of TypeError""

This reverts commit 138f9fa73a2c8d05c3a543a87920f23784f89083.
renamed ConversationError to ConvertError
min