static fun <A : Any!, B : Any!> flatMap(@NonNull list: MutableList<A>, @NonNull function: (in A) -> out MutableIterable<B>!): MutableList<B>!
For the given list of values runs the given function on each list value and stores the returned flattened result in a list. Flattening means that instead of a List of Lists we will get only a joined List of values.
list - MutableList<A>: list of values that are going the be flat mapped
function - (in A) -> out MutableIterable<B>!: function used for flat mapping
Return
MutableList<B>!: list of flat mapped values