syntax_data: {"ast_node_type":"other","tokens":[{"end":58,"kind":"keyword","start":0,"text":"&TestCase::Slice"}]}
source_snippet:                 &TestCase::Slice { len, variable_length },
context_before:                 &TestKind::Len { len: test_len, op: BinOp::Eq },
context_after:             ) => {