The `goog.structs.InversionMap` Class

`goog.structs.InversionMap(rangeArray, valueArray, opt_delta)`

Maps ranges to values using goog.structs.Inversion.

rangeArray {Array.<number>}: An array of monotonically increasing integer values, with at least one instance.
valueArray {Array.<*>}: An array of corresponding values. Length must be the same as rangeArray.
opt_delta {boolean=}: If true, saves only delta from previous value.

`.at(intKey)`

Gets the value corresponding to a number from the inversion map.

intKey {number}: The number for which value needs to be retrieved from inversion map.
returns {*}: Value retrieved from inversion map; null if not found.

`.spliceInversion(rangeArray, valueArray, opt_delta)`

Splices a range -> value map into this inversion map.

rangeArray {Array.<number>}: An array of monotonically increasing integer values, with at least one instance.
valueArray {Array.<*>}: An array of corresponding values. Length must be the same as rangeArray.
opt_delta {boolean=}: If true, saves only delta from previous value.