code: function deduceSize(deducables, index, isPercentageBased, table) {
          if (index < 0 || index >= deducables.length - 1) {
            return "";
          }
  
          var current = deducables[index];
  
          if (current) {
            current = {
              value: current,
              delta: 0
            };
          } else {
            var reversedUpToIndex = deducables.slice(0, index).reverse();
            for (var i = 0; i < reversedUpToIndex.length; i++) {
              if (reversedUpToIndex[i]) {
                current = {
                  value: reversedUpToIndex[i],
                  delta: i + 1
                };
              }
            }
          }
  
          var next = deducables[index + 1];
  
          if (next) {
            next = {
              value: next,
              delta: 1
            };
          } else {
            var rest = deducables.slice(index + 1);
            for (var j = 0; j < rest.length; j++) {
              if (rest[j]) {
                next = {
                  value: rest[j],
                  delta: j + 1
                };
              }
            }
          }
  
          var extras = next.delta - current.delta;
          var pixelWidth = Math.abs(next.value - current.value) / extras;
          return isPercentageBased ? pixelWidth / getComputedStyleSize(table, 'width') * 100 : pixelWidth;
        }
docs: Attempt to deduce the width/height of a column/row that has more than one cell spanned.