code: private String internalGetUriStyleSheet(CmsObject cms, String editedResourcePath) {
  
          if (editedResourcePath == null) {
              return "";
          }
          String result = "";
          try {
              // determine the path of the template
              String templatePath = "";
              try {
                  templatePath = cms.readPropertyObject(
                      editedResourcePath,
                      CmsPropertyDefinition.PROPERTY_TEMPLATE,
                      true).getValue("");
                  if (CmsTemplateContextManager.isProvider(templatePath)) {
                      I_CmsTemplateContextProvider provider = OpenCms.getTemplateContextManager().getTemplateContextProvider(
                          templatePath);
                      if (provider != null) {
                          String providerResult = provider.getEditorStyleSheet(cms, editedResourcePath);
                          if (providerResult != null) {
                              return providerResult;
                          }
                      }
                  }
              } catch (CmsException e) {
                  if (LOG.isWarnEnabled()) {
                      LOG.warn(Messages.get().getBundle().key(Messages.LOG_READ_TEMPLATE_PROP_FAILED_0), e);
                  }
              }
              if (CmsStringUtil.isNotEmpty(templatePath)) {
                  // read the template property value from the template file where the absolute CSS path is (or should be) stored
                  result = cms.readPropertyObject(templatePath, CmsPropertyDefinition.PROPERTY_TEMPLATE, false).getValue(
                      "");
              }
          } catch (CmsException e) {
              if (LOG.isWarnEnabled()) {
                  LOG.warn(Messages.get().getBundle().key(Messages.LOG_READ_TEMPLATE_PROP_STYLESHEET_FAILED_0), e);
              }
          }
          return result;
      }
docs: Finds the style sheet by reading the template property of the template for a given path.<p>
  
  @param cms the current CMS context
  @param editedResourcePath the resource path
  
  @return the CSS uri from the template for the given path