// We use this somewhat weird pattern with an enum for each assertion we want to make as a way
    // of dealing with the fact that one of the assertions is @GwtIncompatible but we don't want to
    // have to have duplicate @GwtIncompatible test methods just to make that assertion.
    for (AssertFailsToDecodeStrategy strategy : AssertFailsToDecodeStrategy.values()) {

    assertThat(e).hasMessageThat().contains("toString representation");
  }

  private static void assertErrorMessage(Throwable e, String message) {
    // TODO(kevinb): use a Truth assertion here
    if (!e.getMessage().contains(message)) {
      fail("expected <" + e.getMessage() + "> to contain <" + message + ">");
    }
  }

  /**

 *
 * @param <K> the type of keys used by the maps under test
 * @param <V> the type of mapped values used the maps under test
 * @author George van den Driessche
 */
// TODO: Descriptive assertion messages, with hints as to probable fixes.
// TODO: Add another constructor parameter indicating whether the class under test is ordered, and
// check the order if so.
// TODO: Refactor to share code with SetTestBuilder etc.

                             /*output_names=*/nullptr,
                             /*opts=*/nullptr, description, s.get());
  ASSERT_EQ(TF_OK, TF_GetCode(s.get())) << TF_Message(s.get());
  ASSERT_NE(*func, nullptr);
}

class CApiExperimentalFunctionTest : public ::testing::Test {
 protected:
  CApiExperimentalFunctionTest()
      : s_(TF_NewStatus()), func_graph_(TF_NewGraph()), func_(nullptr) {}

        if (level == FileInformation.FILE_BASIC_INFO || level == FileInformation.FILE_STANDARD_INFO
                || level == FileInformation.FILE_ENDOFFILE_INFO) {
            // These are valid levels, skip assertion
            return;
        }

        IllegalArgumentException exception =
                assertThrows(IllegalArgumentException.class, () -> Trans2QueryPathInformation.mapInformationLevel(level));

			continue
		}
		// Test passes as expected, but the output values are verified for correctness here.
		if actualErr == nil {
			// Asserting whether the md5 output is correct.
			if expectedMD5, ok := testCase.inputMeta["etag"]; ok && expectedMD5 != objInfo.ETag {
				t.Errorf("Test %d: %s: Calculated Md5 different from the actual one %s.", i, instanceType, objInfo.ETag)

    // need a long enough string for the buffer to hit 0 remaining before the copy completes
    String string = Strings.repeat("0123456789", 100);
    StringBuilder b = new StringBuilder();
    // the main assertion of this test is here... the copy will fail if the buffer size goes down
    // each time it is not filled completely
    long copied = CharStreams.copy(newNonBufferFillingReader(new StringReader(string)), b);

    // need a long enough string for the buffer to hit 0 remaining before the copy completes
    String string = Strings.repeat("0123456789", 100);
    StringBuilder b = new StringBuilder();
    // the main assertion of this test is here... the copy will fail if the buffer size goes down
    // each time it is not filled completely
    long copied = CharStreams.copy(newNonBufferFillingReader(new StringReader(string)), b);

import java.util.List;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A series of tests that support asserting that collections cannot be modified, either through
 * direct or indirect means.
 *
 * @author Robert Konigsberg
 */
@GwtCompatible
@NullMarked
public class UnmodifiableCollectionTests {

}
```

## 🏗️ Architecture & Design Patterns

### Core Design Principles
CoreLib follows a **utility-class pattern** where most functionality is exposed through static methods:

- **Assertion-based validation** - All methods validate inputs using `AssertionUtil.assertArgumentNotNull()` and `AssertionUtil.assertArgumentNotEmpty()`