returns the current element, returns the same element as the previous next call if there is no next before current called then we will call next as initial element
true if additional data is present false if not
looks ahead cnt without changing the internal data "pointers" of the data source (this is mostly needed by possibly infinite constructs like lazy streams, because they do not know by definition their boundaries)
the elements to look ahead
either the element or ITERATION_STATUS.EO_STRM if we hit the end of the stream before finding the "cnt" element
returns the next element in the stream
resets the position to the beginning
defines a sequence of numbers for our stream input