Return the first origin index (integer) of the current list. That
        index refers to it's placement in the original list of dictionaries.
        
        This is very useful when one wants to reference the original entry by
        index.

        Example of use:

        >>> test = [
        ...    {"name": "Jim",   "age": 18, "income": 93000, "order": 2},
        ...    {"name": "Larry", "age": 18,                  "order": 3},
        ...    {"name": "Joe",   "age": 20, "income": 15000, "order": 1},
        ...    {"name": "Bill",  "age": 19, "income": 29000, "order": 4},
        ... ]
        >>> print PLOD(test).returnOneIndex()
        0
        >>> print PLOD(test).sort("name").returnOneIndex()
        3

        :param last:
           The last origin of the current list is returned rather than the first.
        :return:
           An integer representing the original placement of the first item in
           the list. Returns None if the list is currently empty.

def returnOneIndex(self, last=False):
        '''Return the first origin index (integer) of the current list. That
        index refers to it's placement in the original list of dictionaries.
        
        This is very useful when one wants to reference the original entry by
        index.

        Example of use:

        >>> test = [
        ...    {"name": "Jim",   "age": 18, "income": 93000, "order": 2},
        ...    {"name": "Larry", "age": 18,                  "order": 3},
        ...    {"name": "Joe",   "age": 20, "income": 15000, "order": 1},
        ...    {"name": "Bill",  "age": 19, "income": 29000, "order": 4},
        ... ]
        >>> print PLOD(test).returnOneIndex()
        0
        >>> print PLOD(test).sort("name").returnOneIndex()
        3

        :param last:
           The last origin of the current list is returned rather than the first.
        :return:
           An integer representing the original placement of the first item in
           the list. Returns None if the list is currently empty.
        '''
        if len(self.table)==0:
            return None
        else:
            if last:
                return self.index_track.pop()
            else:
                return self.index_track[0]