Build one set of col widths or row heights.

def _compile_dimension_size(self, base_index, array,
                                property, sized_elements):
        """Build one set of col widths or row heights."""
        sort_index = base_index + 2
        sized_elements.sort(key=lambda x: x[sort_index])
        for element_data in sized_elements:
            start, end = element_data[base_index], element_data[sort_index]
            end += start
            element, size = element_data[4:6]

            # Find the total current size of the set
            set_size = sum(array[start:end]) + (end-start-1)*self.margin

            # Work out the extra space we need
            extra_space_needed = getattr(size, property) - set_size
            if extra_space_needed < 0: continue

            # Distribute it among the entries
            extra_space_each = extra_space_needed / (end-start)
            for index in range(start, end):
                array[index] += extra_space_each