public String summarize(final ExecutionStep<?> step) {
    return summarize(step, "").summary;
  }
@Test
  public void shouldSummarizeWithSource() {
    // Given:
    final LogicalSchema schema = LogicalSchema.builder()
        .keyColumn(SystemColumns.ROWKEY_NAME, SqlTypes.STRING)
        .valueColumn(ColumnName.of("L1"), SqlTypes.STRING)
        .build();

    final ExecutionStep<?> step = givenStep(StreamSelect.class, "child", schema, sourceStep);

    // When:
    final String summary = planSummaryBuilder.summarize(step);

    // Then:
    assertThat(summary, is(
        " > [ PROJECT ] | Schema: ROWKEY STRING KEY, L1 STRING | Logger: QID.child"
            + "\n\t\t > [ SOURCE ] | Schema: ROWKEY STRING KEY, L0 INTEGER | Logger: QID.src\n"
    ));
  }