syntax_data: {"ast_node_type":"other","tokens":[{"end":41,"kind":"keyword","start":0,"text":"x21:"}]}
source_snippet:         x21: reg = ["x21", "s5"] % not_e,
context_before:         x20: reg = ["x20", "s4"] % not_e,
context_after:         x22: reg = ["x22", "s6"] % not_e,