code: public static Symbol symbol(Object o) {
          if (o instanceof Symbol)
              return (Symbol) o;
          else if (o instanceof String) {
              String s = (String) o;
              if (s.charAt(0) == ':')
                  return new SymbolImpl(s.substring(1));
              else
                  return new SymbolImpl(s);
          }
          else throw new IllegalArgumentException("Cannot make symbol from " + o.getClass().getSimpleName());
      }
docs: Converts a string or a symbol to a symbol
  @param o a string or a symbol
  @return a symbol