code: public static boolean isMultivaluedProperty(final Node node, final String propertyName)
              throws RepositoryException {
          return getDefinitionForPropertyName(node, propertyName).map(PropertyDefinition::isMultiple).orElse(true);
      }
docs: Determine if a given JCR property name is single- or multi- valued.
  If unsure, choose the least restrictive option (multivalued = true)
  
  @param node the JCR node to check
  @param propertyName the property name (which may or may not already exist)
  @return true if the property is multivalued
  @throws RepositoryException if repository exception occurred