1. A method including: analyzing, by a processor, a first version of a computer program, the analyzing including identifying a first data processing element included in the first version of the computer program, the first data processing element referencing a first data source external to the first version of the computer program; generating a data source element that represents a second data source different from the first data source; and generating a second version of the computer program, the second version of the computer program including the generated data source element and a second data processing element that is based on the first data processing element; in which, in the second version of the computer program, the second data processing element references the generated data source element.