### 9.2 Thread Safety
- Use concurrent data structures for lease storage
- Minimize lock contention in hot paths
- Async handling of lease breaks

### 9.3 Network Efficiency
- Batch lease requests when possible
- Implement lease key reuse for related files
- Optimize lease break acknowledgment timing

## 10. Error Handling

### 10.1 Lease Break Timeout
```java

    public void test_executePython_blankFilename() {
        pythonJob.filename("");

        try {
            pythonJob.executePython();
            fail("Should throw JobProcessingException");
        } catch (JobProcessingException e) {
            assertEquals("Python script is not specified.", e.getMessage());
        }
    }

    // Test executePython with null filename

        // Test getting non-existent property
        try {
            fessConfig.get("non.existent.property");
            fail("Should throw exception for non-existent property");
        } catch (ConfigPropertyNotFoundException e) {
            // Expected exception
            assertTrue(e.getMessage().contains("non.existent.property"));
        }
    }

    // Test system property without prefix

    void set(T instance, Object value) {
      try {
        field.set(instance, value);
      } catch (IllegalAccessException impossible) {
        throw new AssertionError(impossible);
      }
    }

    void set(T instance, int value) {
      try {
        field.set(instance, value);
      } catch (IllegalAccessException impossible) {
        throw new AssertionError(impossible);
      }
    }
  }

<%@page pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<%-- query did not match any document --%>
<div id="result" class="row">
	<div class="col-md-8 alert alert-info">
		<la:message key="labels.did_not_match" arg0="${displayQuery}" />
	</div>
	<div class="col-md-4"><%-- Side Content --%></div>

{
  "dynamic_templates": [
    {
      "strings": {
        "mapping": {
          "type": "keyword"
        },
        "match": "*",
        "match_mapping_type": "string"
      }
    }
  ],
  "properties": {
    "@timestamp": {
      "type": "date",
      "format": "epoch_millis"
    },
    "docFreq": {
      "type": "long"
    },
    "fields": {
      "type": "keyword"
    },
    "kinds": {

        members:
            - websocket
            - include_router
            - get
            - put
            - post
            - delete
            - options
            - head
            - patch
            - trace

      fail(message);
    } catch (UnsupportedOperationException expected) {
    }
  }

  private void expectReturnsFalseOrThrows(Target target) {
    String message = Platform.format("retainAll(%s) should return false or throw", target);
    try {
      assertFalse(message, collection.retainAll(target.toRetain));
    } catch (UnsupportedOperationException tolerated) {
    }
  }

                if (value == null) {
                    return null;
                }
                try {
                    return Integer.valueOf(value);
                } catch (NumberFormatException e) {
                    return null;
                }
            }

            @Override
            public Long getAsLong(String propertyKey) {

        multiExceptionListIterator.promoteToNext(targetReturnValueFromNext);
      }

      referenceReturnValue = method.execute(reference);
    } catch (PermittedMetaException e) {
      referenceException = e;
    } catch (UnknownElementException e) {
      throw new AssertionError(e);
    }

    if (referenceException == null) {
      if (targetException != null) {