An electronic device includes a card holder for receiving a chip card, and a housing defining a receiving groove for receiving the card holder. Embodiments of the disclosed technique include detecting an error generating change at a specific location in source code of an application without executing the source code. A second set of program segments is stored on a server, with at least one of the first set of program segments having a counterpart in the second set of program segments. A mobile device needs to be plugged into a power source in order to have enough power to generate the signal of required intensity. Placement of the filter in an optimal distal location is thereby achieved. A reinforced element including an upward extension, an improved shear key and stacked arrangement are also disclosed.