text: on_llm_end     NaN     4       2     2       0         0             0       21    on_llm_end     NaN     4       2     2       0         0             0       22    on_llm_end     NaN     4       2     2       0         0             0       23    on_llm_end     NaN     4       2     2       0         0             0               chain_ends  llm_starts  ...  difficult_words  linsear_write_formula  \    0            0           1  ...              NaN                    NaN       1            0