code: protected Constructor<?> getConstructor(Class<?> clazz, Class<?> paramClass) {
          for (Constructor<?> c : clazz.getConstructors()) {
              Class<?>[] paramTypes = c.getParameterTypes();
              if (paramTypes.length != 1) {
                  continue;
              }
              if (paramTypes[0].equals(paramClass)) {
                  return c;
              }
          }
          return null;
      }
docs: Returns the first constructor that has exactly one parameter of the
  provided paramClass type.
  
  @param clazz Class whose constructors we are checking
  @param paramClass Class Parameter class that the constructor should take
  @return Constructor