hashCode implementation of Field is not correct

Two objects can be equal but have different hashcodes - this means they cannot be used as a key in a hashmap!

public boolean equals(Object object)

{ if (super.equals(object) == true) return true; if (!(object instanceof Field)) return false; return tag == ((Field) object).getField() && getObject().equals(((Field) object).getObject()); }

public int hashCode()

{ return object.hashCode(); }