Hugging Face sentence-transformers is a Python framework for state-of-the-art sentence, text and image embeddings. One of the instruct embedding models is used in the HuggingFaceInstructEmbeddings class. 
from langchain_community.embeddings import HuggingFaceInstructEmbeddings

embeddings = HuggingFaceInstructEmbeddings(
    query_instruction="Represent the query for retrieval: "
)

load INSTRUCTOR_Transformer
max_seq_length  512

text = "This is a test document."

query_result = embeddings.embed_query(text)