static boolean isNumber(String s) {
    if (s == null || s.equals(Constants.DATATYPE_NAN)) {
      return false;
    }
    try {
      Double.parseDouble(s);
    } catch (NumberFormatException e) {
      return false;
    }
    return true;
  }
if data type of timeseries is not defined in headers of schema, this method will be called to
do type inference

@param strValue
@return
iotdb-client/cli/src/main/java/org/apache/iotdb/tool/data/AbstractDataTool.java