code: public boolean validate(Entity entity, String attribute) throws APIException, ConnectionException, OidException {
          Asset asset = v1Instance.getAsset(entity.getInstanceKey()) != null ? v1Instance.getAsset(entity.getInstanceKey()) : v1Instance.getAsset(entity.getID());
          IAttributeDefinition attributeDefinition = asset.getAssetType().getAttributeDefinition(attribute);
          return validator.validate(asset, attributeDefinition);
      }
docs: Validate single attribute of an entity.
  
  @param entity - Entity.
  @param attribute - Name of attribute to be validated.
  @return true, if attribute value is valid; false, otherwise.
  @throws OidException
  @throws ConnectionException
  @throws APIException