Tonic water and other tropical posts mixed the powder with soda and sugar, and tonic water was created. The first commercial tonic water was produced in 1858. The mixed drink gin and tonic also originated in British colonial India, when the British mixed their medicinal quinine tonic with gin. Since 2010, at least four tonic syrups have been available in the US. Consumers add carbonated water to the syrup to make tonic water, allowing drinkers to adjust the flavor intensity. Medicinal tonic water originally contained only carbonated water and a large amount of quinine. However, most tonic water today contains less quinine
Component-based software engineering the requirements of the initial component (expressed via the interfaces). Consequently, components can be replaced with either an updated version or an alternative without breaking the system in which the component operates. As a rule of thumb for engineers substituting components, component B can immediately replace component A, if component B provides at least what component A provided and uses no more than what component A used. Software components often take the form of objects (not classes) or collections of objects (from object-oriented programming), in some binary or textual form, adhering to some interface description language (IDL) so that the