List<String> keyAndValue = ImmutableList.copyOf(KEY_VALUE_SPLITTER.split(keyValuePair));
        checkArgument(!keyAndValue.isEmpty(), "blank key-value pair");
        checkArgument(
            keyAndValue.size() <= 2,
            "key-value pair %s with more than one equals sign",
            keyValuePair);

        // Find the ValueParser for the current key.
        String key = keyAndValue.get(0);

        List<String> keyAndValue = ImmutableList.copyOf(KEY_VALUE_SPLITTER.split(keyValuePair));
        checkArgument(!keyAndValue.isEmpty(), "blank key-value pair");
        checkArgument(
            keyAndValue.size() <= 2,
            "key-value pair %s with more than one equals sign",
            keyValuePair);

        // Find the ValueParser for the current key.
        String key = keyAndValue.get(0);

import java.util.Collection;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * A {@code Multimap} that cannot hold duplicate key-value pairs. Adding a key-value pair that's
 * already in the multimap has no effect. See the {@link Multimap} documentation for information
 * common to all multimaps.
 *

import java.util.Collection;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * A {@code Multimap} that cannot hold duplicate key-value pairs. Adding a key-value pair that's
 * already in the multimap has no effect. See the {@link Multimap} documentation for information
 * common to all multimaps.
 *

import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimap} using hash tables.
 *
 * <p>The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an
 * existing key-value pair has no effect.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *

     * The configuration string format is "clientName:pattern,clientName:pattern,..."
     * Results are cached to improve performance on subsequent calls.
     *
     * @param value the client rule configuration string
     * @return a list of pairs containing client names and their corresponding compiled patterns
     */

            if (codes[i] == code) {
                return Optional.of(msgs[i]);
            }
        }
        return Optional.empty();
    }

    // Producer for code->message pairs covering all known constants (happy path)
    static Stream<Arguments> knownCodeMessagePairs() {
        return Stream.of(Arguments.of(WinError.ERROR_SUCCESS, "The operation completed successfully."),

 * given key agrees with the order in which the values were added.
 *
 * <p>This multimap allows duplicate key-value pairs. After adding a new key-value pair equal to an
 * existing key-value pair, the {@code ArrayListMultimap} will contain entries for both the new
 * value and the old value.
 *

import org.jspecify.annotations.Nullable;

/**
 * A {@code SetMultimap} whose set of values for a given key are kept sorted; that is, they comprise
 * a {@link SortedSet}. It cannot hold duplicate key-value pairs; adding a key-value pair that's
 * already in the multimap has no effect. This interface does not specify the ordering of the
 * multimap's keys. See the {@link Multimap} documentation for information common to all multimaps.
 *

      }
    }
  }
  return commaFound
}

private fun Buffer.startsWith(prefix: Byte): Boolean = !exhausted() && this[0] == prefix

/**
 * Reads a double-quoted string, unescaping quoted pairs like `\"` to the 2nd character in each
 * sequence. Returns the unescaped string, or null if the buffer isn't prefixed with a
 * double-quoted string.
 */
@Throws(EOFException::class)