code: function getEastingFromChar(e, set) {
          // colOrigin is the letter at the origin of the set for the
          // column
          var curCol = SET_ORIGIN_COLUMN_LETTERS.charCodeAt(set - 1);
          var eastingValue = 100000.0;
          var rewindMarker = false;
  
          while (curCol !== e.charCodeAt(0)) {
              curCol++;
              if (curCol === I) {
                  curCol++;
              }
              if (curCol === O) {
                  curCol++;
              }
              if (curCol > Z) {
                  if (rewindMarker) {
                      throw ("Bad character: " + e);
                  }
                  curCol = A;
                  rewindMarker = true;
              }
              eastingValue += 100000.0;
          }
  
          return eastingValue;
      }
docs: Given the first letter from a two-letter MGRS 100k zone, and given the
  MGRS table set for the zone number, figure out the easting value that
  should be added to the other, secondary easting value.
  
  @private
  @param {char} e The first letter from a two-letter MGRS 100´k zone.
  @param {number} set The MGRS table set for the zone number.
  @return {number} The easting value for the given letter and set.