### Question:
PostgresSupport { @Support({SQLDialect.POSTGRES}) public static <T> Field<T[]> arrayAgg(Field<T> field) { return DSL.field("array_agg({0})", field.getDataType().getArrayDataType(), field); } private  PostgresSupport(); @Support({SQLDialect.POSTGRES}) static Field<T[]> arrayAgg(Field<T> field); @Support({SQLDialect.POSTGRES}) static Field<T[]> arrayAggNoNulls(Field<T> field); @Support({SQLDialect.POSTGRES}) static Field<String> stringAgg(Field<String> field, String delimiter);  }### Answer:
@Test public void appliesArrayAggGroupingFunction() { Field<Integer[]> agg = PostgresSupport.arrayAgg(Table1.FIELD_ID1); assertThat(agg.toString()).isEqualTo("array_agg(" + Table1.FIELD_ID1.toString() + ")"); }