* only if this iterator passed across threads,
       * which we don't support anyway.
       */
      return nextIndex >= 0;
    }

    /**
     * Checks whether nextIndex is valid; if so setting nextItem. Stops iterator when either hits
     * putIndex or sees null item.
     */
    private void checkNext() {
      if (nextIndex == putIndex) {
        nextIndex = -1;
        nextItem = null;

        </field>
        <field>
          <name>checksumPolicy</name>
          <version>1.0.0+</version>
          <description>
            What to do when verification of an artifact checksum fails. Valid values are "fail" (default for Maven 4 and
            above), "warn" (default for Maven 3) or "ignore".
          </description>
          <type>String</type>
        </field>
      </fields>
    </class>

		jbytes, err := json.Marshal(healSequenceStatus{
			Summary: healFinishedStatus,
		})
		return jbytes, toAdminAPIErrCode(GlobalContext, err)
	}

	// Check if client-token is valid
	if clientToken != h.clientToken {
		return nil, ErrHealInvalidClientToken
	}

	// Take lock to access and update the heal-sequence
	h.mutex.Lock()
	defer h.mutex.Unlock()

			selected = entry
			continue
		}

		// Get new entry metadata,
		// shallow decode.
		xl, err := entry.xlmeta()
		if err != nil {
			continue
		}
		objsValid++

		// Add all valid to candidates.
		r.candidates = append(r.candidates, xl.versions)

		// We select the first object we find as a candidate and see if all match that.
		// This is to quickly identify if all agree.
		if selected == nil {

          escapedInput.append(c);
        } else {
          escapedInput.append(String.format("\\u%04x", (int) c));
        }
      }
      fail("FLOATING_POINT_PATTERN should have matched valid input <" + escapedInput + ">");
    }
  }

  @GwtIncompatible // Doubles.tryParse
  private static void checkTryParse(double expected, String input) {

      assertTrue(
          LongMath.biggestBinomials[k] == Integer.MAX_VALUE
              || !fitsInLong(BigIntegerMath.binomial(LongMath.biggestBinomials[k] + 1, k)));
      // In the first case, any long is valid; in the second, we want to test that the next-bigger
      // long overflows.
    }
    int k = LongMath.biggestBinomials.length;
    assertFalse(fitsInLong(BigIntegerMath.binomial(2 * k, k)));

            UpgradeResult result = strategy.apply(context, pomMap);

            // Should succeed
            assertTrue(result.success(), "Valid upgrade should be successful");
            assertEquals(0, result.errorCount(), "Should have no errors");
            assertEquals(1, result.modifiedCount(), "Should have modified one POM");
        }
    }

      WrappedIterator(Iterator<V> delegateIterator) {
        this.delegateIterator = delegateIterator;
      }

      /**
       * If the delegate changed since the iterator was created, the iterator is no longer valid.
       */
      void validateIterator() {
        refreshIfEmpty();
        if (delegate != originalDelegate) {
          throw new ConcurrentModificationException();
        }
      }

Another big feature needed by APIs is data validation, making sure that the data is valid, given certain parameters. For example, that some field is an `int`, and not some random string. This is especially useful for incoming data.

Without a data validation system, you would have to do all the checks by hand, in code.

        int numHashFunctions,
        LockFreeBitArray bits);

    /**
     * Identifier used to encode this strategy, when marshalled as part of a BloomFilter. Only
     * values in the [-128, 127] range are valid for the compact serial form. Non-negative values
     * are reserved for enums defined in BloomFilterStrategies; negative values are reserved for any