'Return the item position, if it exists.
An item exist in the list if:
* end is < 0
* item_type is matching
Return -1 if the item is not found.'

def __itemexist__(self, item_type):

    for i in range(self.len()):
        if ((self.logs_list[i][1] < 0) and (self.logs_list[i][3] == item_type)):
            return i
    return (-1)
