@Override
        public String pathVariable(PathMappingType type) {
            checkArgument(type == PathMappingType.GLOB || type == PathMappingType.REGEX,
                          "'**' path segment is not supported by '%s' type", type);
            if (type == PathMappingType.GLOB) {
                return StringUtil.toString(pathVarIndex);
            } else {
                return 'p' + StringUtil.toString(pathVarIndex);
            }
        }
Returns whether the specified {@link PathMappingType} is supported by
this {@link PathSegment}.
grpc/src/main/java/com/linecorp/armeria/server/grpc/HttpJsonTranscodingPathParser.java