Particular embodiments generally relate to providing recommendations to users. With some of the described techniques, an executable program is generated based upon expressions of those data parallel tasks. A piston cap is disposed within the valve body and has a wall along which the piston is guided. Alternatively or additionally, the fluid container may include a first data fixture component and the delivery device may include a second data fixture component that cooperates with the first data fixture component of the fluid container to verify compatibility of the fluid container with the delivery device. The guide wire sleeve may be a separate component from the remainder of the outer tubular member to facilitate efficient manufacture.