protected void addExpression(CrosstabMeasureBuilder<?> crosstabMeasure) {
Validate.notNull(crosstabMeasure, "crosstabMeasure must not be null");
this.expressions.add(Expressions.crosstabValue(crosstabMeasure));
}
protected void addExpression(AbstractCrosstabGroupBuilder<?, ?, ?> crosstabGroup) {
Validate.notNull(crosstabGroup, "crosstabGroup must not be null");
this.expressions.add(Expressions.crosstabValue(crosstabGroup));
}