code: public boolean checkboxColumnSelect(String searchText) {
          boolean selected = false;
          if (ready(true)) {
              String path;
              int rowIndex = getRowIndex(searchText);
              if (rowIndex != -1) {
                  path = getRow(rowIndex).getXPath() + "//div[contains(@class,'x-grid3-check-col')]";
                  WebLocator element = new WebLocator().setElPath(path);
                  if (element.ready()) {
                      // TODO (verify if is working) to scroll to this element (if element is not visible)
                      WebLocator locator = new WebLocator(this).setElPath("//*[contains(@class,'x-grid3-focus')]");
                      locator.sendKeys(Keys.TAB);
                      selected = isCheckBoxColumnSelected(searchText) || element.click();
                      LOGGER.info("Clicking on checkboxColumnSelect corresponding to line : " + searchText);
                  } else {
                      LOGGER.warn("Could not click on checkboxColumnSelect corresponding to line : " + searchText + "; path = " + path);
                      return false;
                  }
              }
          } else {
              LOGGER.warn("checkboxColumnSelect: grid is not ready for use: " + toString());
              selected = false;
          }
          return selected;
      }
docs: clicks in the checkbox found at the beginning of the grid which contains a specific element
  
  @param searchText searchText
  @return true or false