docs: public final long asScalarLong() {
          verifyTableInvariants();
  
          if (m_rowCount != 1) {
              throw new IllegalStateException(
                      "table must contain exactly 1 tuple; tuples = " + m_rowCount);
          }
          if (m_colCount != 1) {
              throw new IllegalStateException(
                      "table must contain exactly 1 column; columns = " + m_colCount);
          }
          final VoltType colType = getColumnType(0);
          switch (colType) {
          case TINYINT:
              final byte tinyInt = m_buffer.get(m_rowStart + 8);
              m_wasNull = (tinyInt == VoltType.NULL_TINYINT);
              return tinyInt;
          case SMALLINT:
              final short smallInt = m_buffer.getShort(m_rowStart + 8);
              m_wasNull = (smallInt == VoltType.NULL_SMALLINT);
              return smallInt;
          case INTEGER:
              final int integer = m_buffer.getInt(m_rowStart + 8);
              m_wasNull = (integer == VoltType.NULL_INTEGER);
              return integer;
          case BIGINT:
              final long bigInt = m_buffer.getLong(m_rowStart + 8);
              m_wasNull = (bigInt == VoltType.NULL_BIGINT);
              return bigInt;
          default:
              throw new IllegalStateException(
                      "table must contain exactly 1 integral value; column 1 is type = " + colType.name());
          }
      }