return charSequence instanceof String
        ? new StringCharSource((String) charSequence)
        : new CharSequenceCharSource(charSequence);
  }

  /**
   * Returns an immutable {@link CharSource} that contains no characters.
   *
   * @since 15.0
   */
  public static CharSource empty() {
    return EmptyCharSource.INSTANCE;
  }

        // When
        String result = trans2GetDfsReferral.toString();

        // Then
        assertNotNull(result);
        assertTrue(result.contains("Trans2GetDfsReferral"));
        assertTrue(result.contains("maxReferralLevel=0x3"));
        assertTrue(result.contains("filename=" + filename));
    }

    @Test
    @DisplayName("toString should handle null path")
    void testToStringWithNullPath() {

import com.google.errorprone.annotations.Immutable;
import com.google.errorprone.annotations.InlineMe;

/**
 * A {@link ValueGraph} whose elements and structural relationships will never change. Instances of
 * this class may be obtained with {@link #copyOf(ValueGraph)}.
 *
 * <p>See the Guava User's Guide's <a
 * href="https://github.com/google/guava/wiki/GraphsExplained#immutable-implementations">discussion

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE components PUBLIC "-//DBFLUTE//DTD LastaDi 1.0//EN"
	"http://dbflute.org/meta/lastadi10.dtd">
<components namespace="fessCrawler">
	<include path="crawler/container.xml" />

	<component name="contentLengthHelper"
		class="org.codelibs.fess.crawler.helper.ContentLengthHelper" instance="singleton">
		<property name="defaultMaxLength">10485760</property><!-- 10M -->
		<postConstruct name="addMaxLength">

        String json = item.toJsonString();

        assertNotNull(json);
        assertTrue(json.contains("\"" + FieldNames.TEXT + "\":\"json test\""));
        assertTrue(json.contains("\"" + FieldNames.QUERY_FREQ + "\":10"));
        assertTrue(json.contains("\"" + FieldNames.TAGS + "\""));
        assertTrue(json.contains("tag1"));
    }

    @Test
    public void testKindEnum() {
        // Test Kind enum

    for (ImmutableTable<Character, Integer, String> testInstance : getTestInstances()) {
      assertTrue(testInstance.contains('a', 1));
      assertTrue(testInstance.contains('b', 1));
      assertTrue(testInstance.contains('a', 2));
      assertFalse(testInstance.contains('b', 2));
      assertFalse(testInstance.contains('c', 3));
    }
  }

  public void testContainsColumn() {

            builder.startObject();
            if (fieldSet.contains(CLUSTER_NAME)) {
                builder.field(CLUSTER_NAME, response.getClusterName());
            }
            if (fieldSet.contains(STATUS)) {
                builder.field(STATUS, response.getStatus().name().toLowerCase(Locale.ROOT));
            }
            if (fieldSet.contains(TIMED_OUT)) {
                builder.field(TIMED_OUT, response.isTimedOut());

        String str = info.toString();
        assertTrue(str.contains("/test/file.txt"));
        assertTrue(str.contains("PERSISTENT"));
        assertTrue(str.contains(testGuid.toString()));
    }

        assertTrue(infoString.contains("alloc=1000"), "toString should contain alloc");
        assertTrue(infoString.contains("free=500"), "toString should contain free");
        assertTrue(infoString.contains("sectPerAlloc=100"), "toString should contain sectPerAlloc");
        assertTrue(infoString.contains("bytesPerSect=512"), "toString should contain bytesPerSect");
    }

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE components PUBLIC "-//DBFLUTE//DTD LastaDi 1.0//EN"
	"http://dbflute.org/meta/lastadi10.dtd">
<components namespace="fessCrawler">
	<include path="crawler/container.xml"/>
	<include path="crawler/client.xml"/>
	<include path="crawler/rule.xml"/>
	<include path="crawler/filter.xml"/>
	<include path="crawler/interval.xml"/>
	<include path="crawler/extractor.xml"/>
	<include path="crawler/mimetype.xml"/>