@Override
        public Object[] toArray() {
          /*
           * standardToArray returns `@Nullable Object[]` rather than `Object[]` but only because it
           * can be used with collections that may contain null. This collection is a collection of
           * non-null Entry objects (Entry objects that might contain null values but are not
           * themselves null), so we can treat it as a plain `Object[]`.
           */

  // Double#doubleToRawLongBits(double)} spec.
  static final long SIGN_MASK = 0x8000000000000000L;

  static final int SIGNIFICAND_BITS = 52;

  static final int EXPONENT_BIAS = 1023;

  /** The implicit 1 bit that is omitted in significands of normal doubles. */
  static final long IMPLICIT_BIT = SIGNIFICAND_MASK + 1;

  static long getSignificand(double d) {
    checkArgument(isFinite(d), "not a normal value");

While there are competing ways to represent absence (`Optional`, "Null Object" pattern, method overloads),
it is unlikely that we'll be able to remove `null` entirely.

After migrating to Java 8, we can use pluggable type checkers to ensure that our annotations are consistent, 
and there are no missing null checks.

## Decision

Use "NullAway" in JSpecify mode to check for null-related errors in Java code.

import static java.util.Objects.requireNonNull;

/**
 * Represents the list of core extensions configured at one source. The list is validated (are GA unique), but no
 * other logic than that is applied.
 *
 * @since 4.0.0
 * @param source The source file of core extensions, is never {@code null}.

    }

    /**
     * Generates the NT password hash for the given password.
     * This version accepts char[] for better security.
     *
     * @param password the password to hash as char array
     * @return nt password hash
     */
    public static byte[] getNTHash(final char[] password) {
        if (password == null) {
            throw new NullPointerException("Password parameter is required");

    }

    /**
     * Number of set bits (1s).
     *
     * <p>Note that because of concurrent set calls and uses of atomics, this bitCount is a (very)
     * close *estimate* of the actual number of bits set. It's not possible to do better than an
     * estimate without locking. Note that the number, if not exactly accurate, is *always*
     * underestimating, never overestimating.
     */

      return;
    }
    fail("Should have failed");
  }

  /** An interface for the 2 ways that a chaining call might be defined. */
  private interface ChainingCalls {
    // A method that is defined to 'return this'
    @CanIgnoreReturnValue
    ChainingCalls chainingCall();

    // A method that just happens to return a ChainingCalls object
    ChainingCalls nonChainingCall();
  }

        .certificatePinner(certificatePinner)
        .build()

    // Add a bad intermediate CA and have that issue a rogue certificate for localhost. Prepare
    // an SSL context for an attacking webserver. It includes both these rogue certificates plus the
    // trusted good certificate above. The attack is that by including the good certificate in the
    // chain, we may trick the certificate pinner into accepting the rouge certificate.

  PrimitiveSink putBoolean(boolean b);

  /** Puts a character into this sink. */
  @CanIgnoreReturnValue
  PrimitiveSink putChar(char c);

  /**
   * Puts each 16-bit code unit from the {@link CharSequence} into this sink.
   *
   * <p><b>Warning:</b> This method will produce different output than most other languages do when
   * running on the equivalent input. For cross-language compatibility, use {@link #putString},

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//