True iff object is an associative map.
True iff amap contains an association for key.
True iff amap has no associations.
True iff the associations in amap1 are the same as the associations in amap2. This means that amap1 and amap2 have the same keys (in the sense of their shared equality predicate), and that for each key they have the same value (in the sense of value-comparator).
True iff amap is mutable.