class_docstr: A DataSeries that holds values in a sequence in memory.
  
  :param maxLen: The maximum number of values to hold.
      Once a bounded length is full, when new items are added, a corresponding number of items are discarded from the
      opposite end. If None then dataseries.DEFAULT_MAX_LEN is used.
  :type maxLen: int.
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docstr: Appends a value with an associated datetime.
  
  .. note::
      If dateTime is not None, it must be greater than the last one.
docstr_tok: ["Appends","a","value","with","an","associated","datetime",".","..","note",":",":","If","dateTime","is","not","None",",","it","must","be","greater","than","the","last","one","."]
code: def appendWithDateTime(self, dateTime, value):
      """
      Appends a value with an associated datetime.
  
      .. note::
          If dateTime is not None, it must be greater than the last one.
      """
  
      if (
          dateTime is not None
          and len(self.__dateTimes) != 0
          and self.__dateTimes[-1] >= dateTime
      ):
          raise Exception(
              "Invalid datetime. It must be bigger than that last one"
          )
  
      assert len(self.__values) == len(self.__dateTimes)
      self.__dateTimes.append(dateTime)
      self.__values.append(value)
  
      self.getNewValueEvent().emit(self, dateTime, value)
  
imports: import abc
  import six
  from six.moves import xrange
  from pyalgotrade import observer
  from pyalgotrade.utils import collections
label_desc: Use image node_id 9 for calling the SequenceDataSeries obj's underlying member method code with example usage: obj.appendWithDateTime(dateTime, value) without return types