code: private long getFirstSecTerForPrimary(int index) {
          long secTer = elements[index];
          if((secTer & SEC_TER_DELTA_FLAG) == 0) {
              // No sec/ter delta.
              return Collation.COMMON_SEC_AND_TER_CE;
          }
          secTer &= ~SEC_TER_DELTA_FLAG;
          if(secTer > Collation.COMMON_SEC_AND_TER_CE) {
              // Implied sec/ter.
              return Collation.COMMON_SEC_AND_TER_CE;
          }
          // Explicit sec/ter below common/common.
          return secTer;
      }
docs: Returns the first secondary & tertiary weights for p where index=findPrimary(p)+1.