syntax_data: {"ast_node_type":"other","tokens":[{"end":61,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // a read with a non-zero-sized buffer and get Ok(0).
context_before:         // But we are not guaranteed to be at the end of the file, because we did not attempt to do
context_after:         // So we do small read to a fixed-size buffer. If the read returns no bytes then we're