are the docs outdated?
from llama_index import GPTSimpleVectorIndex, GPTListIndex
index1 = GPTSimpleVectorIndex.from_documents(documents1)
index2 = GPTSimpleVectorIndex.from_documents(documents2)
# Set summary text
# you can set the summary manually, or you can
# generate the summary itself using LlamaIndex
index1.set_text("summary1")
index2.set_text("summary2")raises an error: AttributeError: 'GPTSimpleVectorIndex' object has no attribute 'set_text'
furthermore,
index3 = GPTListIndex([index1, index2])
raises an error: ValueError: nodes must be a list of Node objects.
