No values, binwidth 0 should fail.
No values, binwidth 1 should fail.
One value, binwidth 1:
( 1 )
1, 2, 3, 4, 5, binwidth 1:
( 1 2 3 4 5 )
1, 2, 3, 4, 5, binwidth 2:
( 1.5 2.5 3.5 4.5 )