code: def _join_texts(df, mark_fields=False):
      "Join texts in row `idx` of `df`, marking each field with `FLD` if `mark_fields=True`"
      text_col = (f"{FLD} {1} " if mark_fields else "") + df.iloc[
          :, 0
      ].astype(str)
      for i in range(1, len(df.columns)):
          text_col += (
              f" {FLD} {i+1} " if mark_fields else " "
          ) + df.iloc[:, i].astype(str)
      return text_col.values
  
imports: from __future__ import annotations
  from ..torch_basics import *
  from ..data.all import *
  import html
label_desc: Use image node_id 15 for calling a global function with example usage: _join_texts(df, mark_fields) and returns: text_col