ERROR: Message '++' not understood.
RECEIVER:
Instance of IdentityDictionary {    (0x1188ea1f8, gc=84, fmt=00, flg=00, set=03)
  instance variables [5]
    array : instance of Array (0x10cd68080, size=432, set=9)
    size : Integer 0
    proto : nil
    parent : instance of IdentityDictionary (0x1188bbbb8, size=5, set=3)
    know : false
}
ARGS:
Instance of IdentityDictionary {    (0x1188bbbb8, gc=01, fmt=00, flg=10, set=03)
  instance variables [5]
    array : instance of Array (0x10cd76200, size=444, set=9)
    size : Integer 108
    proto : nil
    parent : nil
    know : false
}
    ````