docs: public static Chainr fromFile( File chainrSpecFile, ChainrInstantiator chainrInstantiator ) {
          Object chainrSpec;
          try {
              FileInputStream fileInputStream = new FileInputStream( chainrSpecFile );
              chainrSpec = JsonUtils.jsonToObject( fileInputStream );
          } catch ( Exception e ) {
              throw new RuntimeException( "Unable to load chainr spec file " + chainrSpecFile.getAbsolutePath() );
          }
          return getChainr( chainrInstantiator, chainrSpec );
      }