public static Scheme of(SerializationFormat serializationFormat, SessionProtocol sessionProtocol) {
        final Scheme scheme = SCHEMES.get(
                requireNonNull(serializationFormat, "serializationFormat").uriText() + '+' +
                requireNonNull(sessionProtocol, "sessionProtocol").uriText());
        assert scheme != null;
        return scheme;
    }
Returns the {@link Scheme} of the specified {@link SerializationFormat} and {@link SessionProtocol}.
This method returns the same {@link Scheme} instance for the same combination of
{@link SerializationFormat} and {@link SessionProtocol}.
core/src/main/java/com/linecorp/armeria/common/Scheme.java