code: public static Class<? extends Object> resolveCellType(Cell c) {
          switch (c.getCellType()) {
              case CELL_TYPE_BLANK: { return Object.class; }
              case CELL_TYPE_BOOLEAN: { return Boolean.class; }
              case CELL_TYPE_NUMERIC: { return Double.class; }
              case CELL_TYPE_FORMULA: case CELL_TYPE_STRING: case CELL_TYPE_ERROR: { return String.class; }
              default: { throw new CalculationEngineException(String.format("Cell's type %s is not supported.", c.getCellType())); }
          }
      }
docs: Returns a type of given {@link Cell} value.