import java.util.function.BiFunction;
import java.util.function.Function;

import org.apache.commons.lang3.StringUtils;

import com.google.common.base.CaseFormat;

/**
 * Parameter map that converts between camelCase and snake_case.
 *
 * @param <K> the key type
 * @param <V> the value type
 */
public class ParamMap<K, V> implements Map<K, V> {

    private final Map<K, V> parent;

    /**

 * data store specific parameters with type-safe access methods.
 *
 * <p>The class uses a ParamMap internally which provides case format conversion
 * between camelCase and snake_case parameter names for flexible parameter access.
 * Parameters can be stored as any Object type and retrieved with type conversion
 * support for common types like String.</p>
 *

| Element | Convention | Example |
|---------|------------|---------|
| Classes | PascalCase | `UserService`, `FessBaseAction` |
| Methods | camelCase + verb | `getUserList()`, `setupHtmlData()` |
| Constants | UPPER_SNAKE_CASE | `DEFAULT_PAGE_SIZE` |
| Fields | camelCase | `userPager`, `fessConfig` |

## Log Message Guidelines

- Logger: `LogManager.getLogger(ClassName.class)`

- **Indentation**: 4 spaces (no tabs)
- **Line Length**: 140 characters max
- **License Headers**: Required (use `mvn license:format`)

### Naming & Style

Standard Java conventions (PascalCase classes, camelCase methods, UPPER_SNAKE_CASE constants). Add JavaDoc with `@param`, `@return`, `@throws` for new public APIs.

---

## Quick Reference

### Essential Files

| File | Purpose |
|------|---------|

        TestDataStoreParams testParams = new TestDataStoreParams(paramMap);

        assertEquals("value1", testParams.get("key1"));
    }

    // Test case conversion through ParamMap (camelCase to snake_case)
    @Test
    public void test_caseConversion() {
        dataStoreParams.put("camelCaseKey", "value1");
        // ParamMap should handle case conversion

        QueryBuilder result = request.buildFunctionScoreQuery("test", innerQuery);

        String queryString = result.toString();
        // Should contain docFreq, queryFreq, and userBoost factors (camelCase field names)
        assertTrue("Should contain docFreq", queryString.contains("docFreq"));
        assertTrue("Should contain queryFreq", queryString.contains("queryFreq"));

_fiat.go // Code generated by Fiat Cryptography. DO NOT EDIT. // // Autogenerated: word_by_word_montgomery --lang Go --cmovznz-by-mul --relax-primitive-carry-to-bitwidth 32,64 --public-function-case camelCase --public-type-case camelCase --private-function-case camelCase --private-type-case camelCase --doc-text-before-function-name '' --doc-newline-before-package-declaration --doc-prepend-header 'Code generated by Fiat Cryptography. DO NOT EDIT.' --package-name edwards25519 Scalar 64 '2^252 + 27742317777372353535'...

_fiat.go // Code generated by Fiat Cryptography. DO NOT EDIT. // // Autogenerated: word_by_word_montgomery --lang Go --cmovznz-by-mul --relax-primitive-carry-to-bitwidth 32,64 --public-function-case camelCase --public-type-case camelCase --private-function-case camelCase --private-type-case camelCase --doc-text-before-function-name '' --doc-newline-before-package-declaration --doc-prepend-header 'Code generated by Fiat Cryptography. DO NOT EDIT.' --package-name edwards25519 Scalar 64 '2^252 + 27742317777372353535'...

|   alternation
()  grouping
[]  option (0 or 1 times)
{}  repetition (0 to n times)
</pre>

<p>
Lowercase production names are used to identify lexical (terminal) tokens.
Non-terminals are in CamelCase. Lexical tokens are enclosed in
double quotes <code>""</code> or back quotes <code>``</code>.
</p>

<p>
The form <code>a … b</code> represents the set of characters from