void getRemoteHostNameHappyPath() {
        // Ensures remote host name is sourced from transport and resources are closed
        when(transport.getRemoteHostName()).thenReturn("remote.example");
        String name = handle.getRemoteHostName();
        assertEquals("remote.example", name);
        // try-with-resources should close both
        verify(session).close();

    @Test
    public void testUseAfterClose() {
        keyManager.close();
        assertThrows(IllegalStateException.class, () -> keyManager.storeSessionKey("session", testKey, "AES"));
    }

    @Test
    public void testMultipleCloseCalls() {
        keyManager.storeSessionKey("session", testKey, "AES");

        keyManager.close();
        keyManager.close(); // Should not throw

     */
    private Map<String, List<String>> headers;

    /**
     * Closes the content cache if it is not null.
     *
     * @throws IOException if an I/O error occurs.
     */
    @Override
    public void close() throws IOException {
        if (contentCache != null) {
            contentCache.close();
        }
    }

    /**

        this.dataLength = len;
        this.digest = null; /*
                             * otherwise recycled commands
                             * like writeandx will choke if session
                             * closes in between
                             */
    }

    /**
     * Sets the write mode flags for this request.
     *
     * @param writeMode
     *            the writeMode to set
     */

              return read == 0 ? -1 : read;
            }
            buf[i] = (byte) b;
          }
          return i - off;
        }

        @Override
        public void close() throws IOException {
          reader.close();
        }
      };
    }

    @Override
    public BaseEncoding omitPadding() {
      return (paddingChar == null) ? this : newInstance(alphabet, null);
    }

**Covered Extractors**:
- MsWordExtractor
- MsExcelExtractor
- MsPowerPointExtractor
- TextExtractor

**Test Count**: 8 tests

**Key Scenarios**:
- ✅ Successful extraction closes resources properly
- ✅ Failed extraction includes descriptive error messages
- ✅ Null input stream validation
- ✅ Error messages include file type context

---

### 2. FilenameExtractorEnhancedTest.java

        os.write(testData);
        os.flush();
        os.close();

        // Assert
        // Verify that data was written to the underlying stream through CacheStream
        verify(initialOutputStream).write(testData);
        verify(initialOutputStream).flush();
        verify(initialOutputStream).close();
    }

    /**

   * exists but cannot be used for another exchange, it is closed and this returns null.
   */
  private fun planReuseCallConnection(): ReusePlan? {
    // This may be mutated by releaseConnectionNoEvents()!
    val candidate = call.connection ?: return null

    // Make sure this connection is healthy & eligible for new exchanges. If it's no longer needed
    // then we're on the hook to close it.

		return err
	}

	// Delete the event from store.
	return target.store.Del(key)
}

// Close - does nothing and available for interface compatibility.
func (target *AMQPTarget) Close() error {
	close(target.quitCh)
	if target.conn != nil {
		return target.conn.Close()
	}
	return nil
}

func (target *AMQPTarget) init() error {
	return target.initOnce.Do(target.initAMQP)
}

  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  // DoNotCall wants this to be final, but we want to override it to return more specific types.
  // Inheritance is closed, and all subtypes are @DoNotCall, so this is safe to suppress.
  @SuppressWarnings("DoNotCall")
  public ImmutableCollection<V> removeAll(@Nullable Object key) {
    throw new UnsupportedOperationException();
  }