code: public final void setFloatingPointSeparator(
              @Nullable final CharSequence floatingPointSeparator) {
          if (floatingPointSeparator != null) {
              Condition.INSTANCE.ensureAtMaximum(floatingPointSeparator.length(), 1,
                      "The floating point separator's length must be 1");
          }
          this.floatingPointSeparator = floatingPointSeparator;
      }
docs: Sets the symbol, which should be used to separate floating point numbers for textual
  representation.
  
  @param floatingPointSeparator
  The symbol, which should be set, as an instance of the type {@link CharSequence} or
  null, if the default symbol should be used. The length of the symbol must be 1