prepare() {
        var _a;
        if (this.fMap === undefined) {
            this.fMap = {};
            const fieldsInput = (_a = this.info.fields) !== null && _a !== void 0 ? _a : [];
            for (const field of fieldsInput) {
                this.fMap[field.name] = field;
                this.fMap[field.jsonName] = field;
                this.fMap[field.localName] = field;
            }
        }
    }
Reads proto3 messages in canonical JSON format using reflection information.

https://developers.google.com/protocol-buffers/docs/proto3#json