t.Fatalf("\nwanted: %v \nbut found: %v", errMsgTrim, outBufTrim)
			}

			if c.isValid && outBuf.Len() > 0 {
				t.Fatalf("\nwanted: %v \nbut found: %v", errMsgTrim, outBufTrim)
			}
			outBuf.Reset()
		})
	}