@JvmOverloads fun <K, V> Gen.Companion.map(genK: Gen<K>, genV: Gen<V>, maxSize: Int = 100): Gen<Map<K, V>>Returns a stream of values, where each value is a Map, which contains keys and values generated from the underlying generators.
@JvmOverloads fun <K, V> Gen.Companion.map(gen: Gen<Pair<K, V>>, maxSize: Int = 100): Gen<Map<K, V>>Return
a stream of values, where each value is a Map of Pairs from the given gen
the size of the Map is bounded between [0, maxSize)