return total;
  }

  /**
   * Discards {@code n} characters of data from the reader. This method will block until the full
   * amount has been skipped. Does not close the reader.
   *
   * @param reader the reader to read from
   * @param n the number of characters to skip
   * @throws EOFException if this stream reaches the end before skipping all the characters
   * @throws IOException if an I/O error occurs
   */

         *
         * This method reads characters from the reader and processes them according to the following rules:
         * - ISO control characters and space characters are treated as spaces.
         * - Alphanumeric characters (0-9, A-Z, a-z) are appended to the buffer.
         * - Symbol characters (!-/, :-@, [-`, {-~) are appended to the buffer.

    // which means they are treated as pairs of safe characters).
    builder.setSafeRange(Character.MIN_VALUE, '\uFFFD');
    // Unsafe characters are replaced with the Unicode replacement character.
    builder.setUnsafeReplacement("\uFFFD");

    /*
     * Except for \n, \t, and \r, all ASCII control characters are replaced with the Unicode
     * replacement character.
     *

    }

    /**
     * Strips invalid XML characters from the input string.
     *
     * This method removes characters that are not allowed in XML documents
     * according to the XML 1.0 specification. Valid characters include:
     * - Tab (0x9)
     * - Line feed (0xA)
     * - Carriage return (0xD)
     * - Any character between 0x20 and 0xD7FF
     * - Any character between 0xE000 and 0xFFFD

        for (char c : validChars.toCharArray()) {
            assertTrue("Character '" + c + "' should be a valid URL character", CharUtil.isUrlChar(c));
        }
    }

    public void test_isUrlChar_boundaryChars() {
        // Test boundary characters for ranges
        assertTrue(CharUtil.isUrlChar('a')); // first lowercase

/**
 * Represents a single character mapping rule that defines how input characters are mapped to output characters
 * for text analysis and search processing. This class is used in character mapping dictionaries to transform
 * text during indexing and search operations.
 *
 * <p>Each mapping item consists of one or more input character sequences that are mapped to a single output

import static com.google.common.truth.Truth.assertThat;
import static java.lang.Character.MAX_CODE_POINT;
import static java.lang.Character.MAX_HIGH_SURROGATE;
import static java.lang.Character.MAX_LOW_SURROGATE;
import static java.lang.Character.MIN_HIGH_SURROGATE;
import static java.lang.Character.MIN_LOW_SURROGATE;
import static java.lang.Character.MIN_SUPPLEMENTARY_CODE_POINT;
import static java.nio.charset.StandardCharsets.UTF_8;

        }
        return c;
    }

    /**
     * Merges two characters, handling voiced and semi-voiced sound marks.
     * @param c1 The first character.
     * @param c2 The second character.
     * @return The merged character.
     */
    public static char mergeChar(final char c1, final char c2) {
        if (c2 == 'ﾞ') {

    @Required
    @Size(max = 100)
    public String username;

    /** The password for file authentication (maximum 100 characters). */
    @Size(max = 100)
    public String password;

    /** Additional parameters for file authentication (maximum 1000 characters). */
    @Size(max = 1000)
    public String parameters;

        // Test toString with buffer containing non-printable characters or special unicode
        String unicodeChars = "你好世界"; // "Hello World" in Chinese
        UnicodeString unicodeStringChinese = new UnicodeString(unicodeChars, false);
        assertEquals(unicodeChars, unicodeStringChinese.toString(), "toString should handle unicode characters correctly");