_Converter asNumber(term)

Converts a header value to an instance of int to be used inside a matcher.

Used in matchers like hasResponse and hasHeaders. Used to convert a value - typically a String - to an integer to be used inside another matcher. For example:

   var response = await client.request("/foo").get();
  expect(response, hasResponse(200, null, headers: {
    "headerValue": asNumber(lessThan(4))
  });

Source

_Converter asNumber(dynamic term) =>
    new _Converter(_ConverterType.number, term);