private static String paramIsNullText(int x) {
        return "Parameter " + x + " is null.";
    }
Checks if all parameters are non-null. If a null is detected a 
{@code NullPointerException} is thrown.

@param <T>  array type
@param t0   to check
@param t1   to check
@param t2   to check

@throws NullPointerException  if a null is found in the parameters
common-parent/codegen/src/main/java/com/speedment/common/codegen/internal/util/NullUtil.java