nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/autodiff/samediff/SameDiff.java
public List<DifferentialFunction> exec(List<DifferentialFunction> ops) {
        for (int i = 0; i < ops.size(); i++) {
            Op op = (Op) ops.get(i);
            Nd4j.getExecutioner().exec(op);
        }
        return ops;
    }
public List<DifferentialFunction> exec(List<DifferentialFunction> ops) {
        for (int i = 0; i < ops.size(); i++) {
            Op op = (Op) ops.get(i);
            Nd4j.getExecutioner().exec(op);
        }
        return ops;
    }
Executes the list of operations.
This exec method is for
only invoking operations
rather than creating them

@param ops the list of already created ops
@return the passes in list