### Question:
Group { public AttributeContainer attributes() { return attributes; } private  Group(Builder builder, @Nullable Group parent); AttributeContainer attributes(); Group commonParent(Group other); @Nullable Attribute findAttribute(String name); String findAttributeString(String attName, String defaultValue); Optional<Dimension> findDimension(String name); @Nullable Dimension findDimension(Dimension dim); @Nullable Dimension findDimensionLocal(String shortName); @Nullable EnumTypedef findEnumeration(String name); @Nullable Group findGroupLocal(String groupShortName); Optional<Group> findGroupNested(String groupShortName); @Nullable Variable findVariableByAttribute(String attName, String attValue); @Nullable Variable findVariableLocal(String varShortName); @Nullable Variable findVariableOrInParent(String varShortName); ImmutableList<Dimension> getDimensions(); ImmutableList<EnumTypedef> getEnumTypedefs(); String getFullName(); ImmutableList<Group> getGroups(); NetcdfFile getNetcdfFile(); @Nullable Group getParentGroup(); String getShortName(); ImmutableList<Variable> getVariables(); boolean isParent(Group other); boolean isRoot(); ImmutableList<Dimension> makeDimensionsList(String dimString); String getNameAndAttributes(); @Override String toString(); @Override boolean equals(Object oo); @Override int hashCode(); Builder toBuilder(); static Builder builder();  }### Answer:
@Test public void testAttributes() { Attribute att1 = new Attribute("attName", "value"); Attribute att2 = new Attribute("attName2", "value2"); Group.Builder builder = Group.builder().setName("name").addAttribute(att1).addAttribute(att2); AttributeContainer atts = builder.getAttributeContainer(); assertThat(Iterables.isEmpty(atts)).isFalse(); assertThat(Iterables.size(atts)).isEqualTo(2); assertThat(atts.findAttribute("attName")).isEqualTo(att1); assertThat(atts.findAttributeString("attName", null)).isEqualTo("value"); assertThat(atts.findAttributeString("attName2", null)).isEqualTo("value2"); }