This class invokes the initial method on the given Ruby class. As a courtesy to the user, it unwraps the
DataBag that is given to Initial and passes Ruby just the first Tuple that it contains, as the contract
for the Initial function in Algebraic is that it is given a DataBag with one and only one Tuple. Finally,
it wraps the Ruby output in a Tuple.
Nested Class Summary
Nested classes/interfaces inherited from class org.apache.pig.EvalFunc
This callback method must be implemented by all subclasses. This
is the method that will be invoked on every Tuple of a given dataset.
Since the dataset may be divided up in a variety of ways the programmer
should not make assumptions about state that is maintained between
invocations of this method.