method Http2ServerResponse.prototype.getHeaderNames
Http2ServerResponse.prototype.getHeaderNames(): string[]Deprecated
Returns an array containing the unique names of the current outgoing headers. All header names are lowercase.
response.setHeader('Foo', 'bar');
response.setHeader('Set-Cookie', ['foo=bar', 'bar=baz']);
const headerNames = response.getHeaderNames();
// headerNames === ['foo', 'set-cookie']
string[]