syntax_data: {"ast_node_type":"other","tokens":[{"end":52,"kind":"keyword","start":0,"text":"(\"e\","}]}
source_snippet:     ("e", Unstable(sym::riscv_target_feature), &[]),
context_before:     ("d", Unstable(sym::riscv_target_feature), &["f"]),
context_after:     ("f", Unstable(sym::riscv_target_feature), &["zicsr"]),