public boolean isCredentialsAllowed() {
        return credentialsAllowed;
    }
Determines if cookies are supported for CORS requests.

<p>By default cookies are not included in CORS requests but if {@code isCredentialsAllowed} returns
{@code true} cookies will be added to CORS requests. Setting this value to {@code true} will set the
CORS {@code "Access-Control-Allow-Credentials"} response header to {@code true}.

<p>Please note that cookie support needs to be enabled on the client side as well.
The client needs to opt-in to send cookies by calling:
<pre>{@code
xhr.withCredentials = true;
}</pre>

<p>The default value for {@code 'withCredentials'} is {@code false} in which case no cookies are sent.
Setting {@code this} to {@code true} will include cookies in cross origin requests.

@return {@code true} if cookies are supported.
core/src/main/java/com/linecorp/armeria/server/cors/CorsPolicy.java