1. A method of generating computer instructions, comprising: receiving a sequence of instructions, the sequence having an order in which instructions of the sequence of instructions are to appear relative to each other; receiving selection data representative of a plurality of commands including a special command; and repeatedly selecting one of said plurality of commands, performing, for each iteration of the repeatedly selecting, a check whether the selected command of the plurality of commands is the special command, and outputting a computer instruction to a computer instruction queue based on the checking whether the selected command is the special command, wherein said selecting comprises obtaining a random number and selecting said one of said plurality of commands based on said random number, and wherein said outputting of the computer instruction comprises: outputting to the computer instruction queue a next instruction of said sequence of instructions based on the checking indicating that the selected command is said special command; and outputting to the computer instruction queue an instruction associated with said selected command based on the checking indicating that the selected command is not said special command.