// Make a copy of the supplied metadata to avoid
	// to change the original one.
	defaultMeta := make(map[string]string, len(userMeta))
	for k, v := range userMeta {
		// skip tier metadata when copying metadata from source object
		switch k {
		case metaTierName, metaTierStatus, metaTierObjName, metaTierVersionID:
			continue
		}
		defaultMeta[k] = v
	}

	// remove SSE Headers from source info

	// `ExecObjectLayerAPINilTest` manages the operation.
	ExecObjectLayerAPINilTest(t, nilBucket, nilObject, instanceType, apiRouter, nilReq)
}

// Tests sanity of attempting to copying each parts at offsets from an existing
// file and create a new object. Also validates if the written is same as what we
// expected.
func TestAPICopyObjectPartHandlerSanity(t *testing.T) {
	defer DetectTestLeak(t)()

      // independent of the initial capacity, except that it won't be lower than the threshold
      // computed from that capacity. Because the internal table is only allocated on the first
      // write, we won't see copying because of the new threshold. So it is always OK to use the
      // calculation here.
      return (int) Math.ceil(expectedSize / 0.75);
    }
    return Integer.MAX_VALUE; // any large value
  }

  /**

create a map with initial space to hold <code>n</code> map elements.
The precise behavior is implementation-dependent.
</p>


<h3 id="Appending_and_copying_slices">Appending to and copying slices</h3>

<p>
The built-in functions <code>append</code> and <code>copy</code> assist in
common slice operations.
For both functions, the result is independent of whether the memory referenced