code: protected static void validateBool(String opName, SDVariable v) {
          if (v == null)
              return;
          if (v.dataType() != DataType.BOOL)
              throw new IllegalStateException("Cannot apply operation \"" + opName + "\" to variable \"" + v.getVarName() + "\" with non-boolean point data type " + v.dataType());
      }
docs: Validate that the operation is being applied on a boolean type SDVariable
  
  @param opName Operation name to print in the exception
  @param v      Variable to validate datatype for (input to operation)