docs: public static SpreadMap toSpreadMap(Object[] self) {
          if (self == null)
              throw new GroovyRuntimeException("Fail to convert Object[] to SpreadMap, because it is null.");
          else if (self.length % 2 != 0)
              throw new GroovyRuntimeException("Fail to convert Object[] to SpreadMap, because it's size is not even.");
          else
              return new SpreadMap(self);
      }