syntax = "proto2";

message int32 {
    extensions 1 to 4 [
        declaration = {
            number: 1,
            full_name: ".x1",
            type: ".int32"
        },
        declaration = {
            number: 2,
            full_name: ".x2",
            type: ".int32"
        },
        declaration = {
            number: 3,
            full_name: ".y1",
            type: "int32"
        },
        declaration = {
            number: 4,
            full_name: ".y2",
            type: "int32"
        }
    ];
}

extend .int32 {
    optional .int32 x1 = 1;
    optional int32 x2 = 2;
    optional .int32 y1 = 3;
    optional int32 y2 = 4;
}