code: public ByteVector putLong(final long l) {
          int length = this.length;
          if (length + 8 > data.length) {
              enlarge(8);
          }
          byte[] data = this.data;
          int i = (int) (l >>> 32);
          data[length++] = (byte) (i >>> 24);
          data[length++] = (byte) (i >>> 16);
          data[length++] = (byte) (i >>> 8);
          data[length++] = (byte) i;
          i = (int) l;
          data[length++] = (byte) (i >>> 24);
          data[length++] = (byte) (i >>> 16);
          data[length++] = (byte) (i >>> 8);
          data[length++] = (byte) i;
          this.length = length;
          return this;
      }
docs: Puts a long into this byte vector. The byte vector is automatically
  enlarged if necessary.
  
  @param l
  a long.
  @return this byte vector.