fails:Array#insert returns self
fails:Array#insert inserts objects before the element at index for non-negative index
fails:Array#insert appends objects to the end of the array for index == -1
fails:Array#insert inserts objects after the element at index with negative index
fails:Array#insert pads with nils if the index to be inserted to is past the end
fails:Array#insert can insert before the first element with a negative index
fails:Array#insert raises an IndexError if the negative index is out of bounds
fails:Array#insert does nothing of no object is passed
fails:Array#insert tries to convert the passed position argument to an Integer using #to_int
fails:Array#insert raises a RuntimeError on frozen arrays when the array is modified
fails:Array#insert raises a RuntimeError on frozen arrays when the array would not be modified
