The empty set is always a subset.

Subset Query:duplicate rows A
x

Complete set is a subset (we do not mean proper subset).

Subset Query:duplicate rows A
x
SuiteChildOne.SuiteSetUp
SuiteChildOne.TestOneOne
SuiteChildOne.TestOneTwo
SuiteChildOne.SuiteTearDown
SuiteChildOne.SuiteSetUp
SuiteChildOne.TestOneThree
SuiteChildOne.SuiteTearDown

Only some of the rows (in different order) form a subset.

Subset Query:duplicate rows A
x
SuiteChildOne.TestOneTwo
SuiteChildOne.SuiteTearDown
SuiteChildOne.SuiteSetUp
SuiteChildOne.TestOneThree