SNAP TTable LoadSS Adding Extra Row

[hcars]

When loading a SNAP TTable with LoadSS, new columns are added mysteriously. Below is an example of the problem:

Input File:

"test_graph6.1.mapping.txt"

# original_id	new_id
d	0
c	1
b	2
a	3

Python shell:

>>> import snap
>>> schema = snap.Schema()
>>> schema.Add(snap.TStrTAttrPr("original_id", snap.atStr))
0
>>> schema.Add(snap.TStrTAttrPr("new_id", snap.atInt))
1
>>> context = snap.TTableContext()
>>> ttable = snap.TTable.LoadSS(schema, "test_graph6.1.mapping.txt", context, "\t", snap.TBool(False))
>>> ttable.SaveSS("test.out")

Output file:
test.out

# original_id	new_id	_id
d	0	0
c	1	1
b	2	2
a	3	3