ImmutableMap.Builder should have remove method

Without Builder.remove() method, it will be very inefficient to create a new immutable map from an existing immutable map removing a key:

Map newMapWithoutKey1 = ImmutableMap.builder()
    .putAll(map)
    .remove("key1")
    .build();

[kluever]

That seems fine to me.

If you’re super worried about performance, you can add the entries from the existing mutable map to the ImmutableMap builder in a loop, and just don’t add the entry if it has a certain key (the key you want to “remove”).

Or, alternatively, use a lazy Maps.filterKeys() and Predicate.not(badKey), wrapped in ImmutableMap.copyOf().

[kluever]

That sounds approximately correct, yes.