(Changed in version 2.8.0) keys returns Iterable[A] rather than Iterator[A].
(Changed in version 2.9.0) The behavior of scanRight has changed. The previous behavior can be reproduced with scanRight.reverse.
(Changed in version 2.9.0) transpose throws an IllegalArgumentException if collections are not uniformly sized.
(Changed in version 2.8.0) values returns Iterable[B] rather than Iterator[B].
Builds a map in which keys are case insensitive