it('keeps containing all values when removed value was not existing in it (only upper case list)', () => {
      expect(valueListOnlyUpper.includes(VaLuE.toUpperCase())).to.equal(true)
      valueListOnlyUpper.remove(anotherValue)
      expect(valueListOnlyUpper.includes(VaLuE.toUpperCase())).to.equal(true)
    })