class_docstr: Stores all actual data and typing information for an entityset
  
  Attributes:
      id
      dataframe_dict
      relationships
      time_type
  
  Properties:
      metadata
class_docstr_tok: ["Stores","all","actual","data","and","typing","information","for","an","entityset","Attributes",":","id","dataframe_dict","relationships","time_type","Properties",":","metadata"]
docstr: Is the forward path from start to end unique?
  
  This will raise if there is no such path.
docstr_tok: ["Is","the","forward","path","from","start","to","end","unique","?","This","will","raise","if","there","is","no","such","path","."]
code: def has_unique_forward_path(
      self, start_dataframe_name, end_dataframe_name
  ):
      """
      Is the forward path from start to end unique?
  
      This will raise if there is no such path.
      """
      paths = self.find_forward_paths(
          start_dataframe_name, end_dataframe_name
      )
  
      next(paths)
      second_path = next(paths, None)
  
      return not second_path
  
imports: import copy
  import logging
  import warnings
  from collections import defaultdict
  import numpy
  import pandas
  from woodwork import init_series
  from woodwork.logical_types import Datetime, LatLong
  from featuretools.entityset import deserialize, serialize
  from featuretools.entityset.relationship import Relationship, RelationshipPath
  from featuretools.feature_base.feature_base import _ES_REF
  from featuretools.utils.gen_utils import Library, import_or_none, is_instance
  from featuretools.utils.plot_utils import check_graphviz, get_graphviz_format, save_graph
  from featuretools.utils.wrangle import _check_timedelta
label_desc: Use image node_id 28 for calling the EntitySet obj's underlying member method code with example usage: obj.has_unique_forward_path(start_dataframe_name, end_dataframe_name) and returns: unknown