### Question:
StructureImpl implements Structure { @Override public boolean hasMember(final String fieldName) { final String upperName = fieldName == null ? null : fieldName.toUpperCase(Locale.getDefault()); return fieldsMap.containsKey(upperName); } StructureImpl(final Map<String, Field> fields); @Override Field getField(final String fieldName); @Override List<Field> getFields(); @Override DataType getType(final String fieldName); @Override boolean hasMember(final String fieldName);  }### Answer:
@Test public void testHasMember() { assertThat(structure.hasMember(FIELD_NAME.toLowerCase())).isTrue(); }
@Test public void testNotHasMember() { assertThat(structure.hasMember("NO SUCH FIELD")).isFalse(); }