@Override
    public String toString() {
        return "StageImpl{" +
            "identifier=" + identifier +
            ", predicates=" + predicates +
            ", joinType=" + joinType +
            ", field=" + field +
            ", joinOperator=" + joinOperator +
            ", foreignFirstField=" + foreignFirstField +
            ", referencedStage=" + referencedStage +
            '}';
    }
@author Per Minborg
@param <T> entity types for this Stage
runtime-parent/runtime-join/src/main/java/com/speedment/runtime/join/internal/stage/StageImpl.java