wp-includes/SimplePie/src/HTTP/Parser.php:179See if the next character is LWS
bool protected function is_linear_whitespace() { return (bool) ($this->data[$this->position] === "\x09" || $this->data[$this->position] === "\x20" || ($this->data[$this->position] === "\x0A" && isset($this->data[$this->position + 1]) && ($this->data[$this->position + 1] === "\x09" || $this->data[$this->position + 1] === "\x20"))); }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/SimplePie/src/HTTP/Parser.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.