code: public Attribute getLookupAttribute(String lookupAttrName) {
      return stream(getLookupAttributes())
          .filter(lookupAttr -> lookupAttr.getName().equals(lookupAttrName))
          .findFirst()
          .orElse(null);
    }
docs: Get lookup attribute by name (case insensitive), returns null if not found
  
  @param lookupAttrName lookup attribute name
  @return lookup attribute or <tt>null</tt>