Analyze the sentiment expressed in the tweet. Is it positive, negative, or neutral? Explain the sentiment in relation to the stock mentioned.
TWEET: "RT @BP_plc: #BP is shifting its upstream portfolio towards #NatGas 🔥 - here's why: https://t.co/42boaDOh3e https://t.co/Ic8jSp4QLA" STOCK: nan DATE: nan
Sentiment: (Provide sentiment here)
Explanation: The tweet sentiment is related to the stock mentioned, and it's important to interpret the context. The LSTM polarity score is nan and the TextBlob polarity score is nan.