code: void setSize(int size) {
          if (this.size != 0) {
              final String fmt = "column size is known: %d";
              final String msg = format(fmt, this.size);
              throw new IllegalStateException(msg);
          }
          this.size = size;
          this.hash = hash();
      }
docs: Sets the column's size and recalculates its hash.
  
  @param size Number of bytes defining this {@link Column column}