code: def timestamp_diff(
      time_point_unit: TimePointUnit, time_point1, time_point2
  ) -> Expression:
      """
      Returns the (signed) number of :class:`~pyflink.table.expression.TimePointUnit` between
      time_point1 and time_point2.
  
      For example,
      `timestamp_diff(TimePointUnit.DAY, lit("2016-06-15").to_date, lit("2016-06-18").to_date`
      leads to 3.
  
      :param time_point_unit: The unit to compute diff.
      :param time_point1: The first point in time.
      :param time_point2: The second point in time.
      :return: The number of intervals as integer value.
      """
      return _ternary_op(
          "timestampDiff",
          time_point_unit._to_j_time_point_unit(),
          time_point1,
          time_point2,
      )
  
imports: from typing import Union
  from pyflink import add_version_doc
  from pyflink.java_gateway import get_gateway
  from pyflink.table.expression import Expression, _get_java_expression, TimePointUnit, JsonOnNull
  from pyflink.table.types import _to_java_data_type, DataType
  from pyflink.table.udf import UserDefinedFunctionWrapper
  from pyflink.util.java_utils import to_jarray, load_java_class
label_desc: Use image node_id 26 for calling a global function with example usage: timestamp_diff(time_point_unit, time_point1, time_point2) and returns: _ternary_op