return new SampleElements<>(
        mapEntry("one", "January"),
        mapEntry("two", "February"),
        mapEntry("three", "March"),
        mapEntry("four", "April"),
        mapEntry("five", "May"));
  }

  @Override
  public SampleElements<String> sampleKeys() {
    return new SampleElements<>("one", "two", "three", "four", "five");
  }

  @Override

    opt Raise other exception
        tasks -->> tasks: Handle exceptions in the background task code
    end
```

/// info

Only **one response** will be sent to the client. It might be one of the error responses or it will be the response from the *path operation*.

After one of those responses is sent, no other response can be sent.

///

/// tip

stands for one item (parameter or result) of the specified type and
all non-<a href="#Blank_identifier">blank</a> names in the signature
must be <a href="#Uniqueness_of_identifiers">unique</a>.
If absent, each type stands for one item of that type.
Parameter and result
lists are always parenthesized except that if there is exactly
one unnamed result it may be written as an unparenthesized type.

import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;

 */

package com.google.common.collect.testing.google;

import static com.google.common.collect.testing.features.CollectionFeature.NON_STANDARD_TOSTRING;
import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;

import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.ONE;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.Multimap;
import com.google.common.collect.testing.features.CollectionFeature;

import static com.google.common.collect.testing.Helpers.mapEntry;
import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;

    Collection<Entry<K, V>> entries = getSampleEntries(getNumEntries() - 1);
    entries.add(entry(null, v3()));
    Map<K, V> other = newHashMap(entries);

    assertFalse(
        "Two Maps should not be equal if exactly one of them contains a null key.",
        getMap().equals(other));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  @MapFeature.Require(ALLOWS_NULL_VALUES)
  public void testEquals_containingNullValue() {

    int initialSize = collection.size();
    assertTrue("remove(present) should return true", collection.remove(e0()));
    assertEquals(
        "remove(present) should decrease a collection's size by one.",
        initialSize - 1,
        collection.size());
    expectMissing(e0());
  }

  @CollectionFeature.Require({SUPPORTS_REMOVE, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
  @CollectionSize.Require(SEVERAL)

   * non-nullable {@code cause}, as many users expect to find one.
   */
  public UncheckedExecutionException(@Nullable String message, @Nullable Throwable cause) {
    super(message, cause);
  }

  /**
   * Creates a new instance with {@code null} as its detail message and the given cause. Prefer to
   * provide a non-nullable {@code cause}, as many users expect to find one.
   */