code: def char_contexts(sentences):
      contexts = []
  
      for sentence in sentences:
          sentence = " ".join([token.text for token in sentence])
  
          for i, char in enumerate(sentence):
              context = f'<span style="background-color: yellow"><b>{char}</b></span>'
              context = "".join(sentence[max(i - 30, 0) : i]) + context
              context = context + "".join(
                  sentence[i + 1 : min(len(sentence), i + 30)]
              )
  
              contexts.append(context)
  
      return contexts
  
file_path: flair/flair/visual/manifold.py
imports: import numpy
  import tqdm
  from sklearn.manifold import TSNE
label_desc: Use image node_id 6 for calling the Visualizer obj's underlying member method code with example usage: obj.char_contexts(sentences) and returns: contexts