1. A method comprising: using a computer to implement: creating a first graphical data flow program in response to user input, wherein the first graphical data flow program includes a plurality of interconnected nodes, wherein the interconnected nodes visually indicate functionality of the first graphical data flow program, and wherein the first graphical data flow program is a data type-generic graphical data flow program; wherein each of the nodes comprises at least one of an input or an output, and wherein for at least a first subset of the nodes, input(s) and/or output(s) for the first subset are not restricted to a specific data type; wherein the first graphical data flow program is executable to perform the functionality for a plurality of different data types; and wherein the first graphical data flow program comprises one set of graphical code that performs the functionality for the plurality of different data types; instantiating a plurality of instances of the first graphical data flow program in a second graphical data flow program, wherein each instance is a data type-specific graphical data flow program; determining if two or more of the instances have same data types; and in response to determining that two or more of the instances have the same data types, replacing one or more of the instances with a reference to a particular instance of the first graphical data flow program with the same data types.