req.Header.Set(k, v)
		}
		if testCase.metadataReplace {
			req.Header.Set("X-Amz-Metadata-Directive", "REPLACE")
		}
		if testCase.metadataCopy {
			req.Header.Set("X-Amz-Metadata-Directive", "COPY")
		}
		if testCase.metadataGarbage {
			req.Header.Set("X-Amz-Metadata-Directive", "Unknown")
		}
		// Since `apiRouter` satisfies `http.Handler` it has a ServeHTTP to execute the logic of the handler.