- Refactor doc load and text load to use a new ServiceSender class,

similar to ServiceRequestor, but one-way.
- This means these two services are now available over websocket with
  document-load and text-load service IDs.

test-api/test-load-document

@@ -0,0 +1,106 @@
+#!/usr/bin/env python3
+
+import requests
+import json
+import sys
+import base64
+
+url = "http://localhost:8088/api/v1/"
+
+############################################################################
+
+text = open("../sources/Challenger-Report-Vol1.pdf", "rb").read()
+
+# Some random identifiers.  The doc ID is important, as extracted knowledge
+# is linked back to this identifier
+org_id = "https://trustgraph.ai/org/1dd51ece-8bd3-48b8-98ce-1ac9164c5214"
+doc_id = "https://trustgraph.ai/doc/72ef3374-af7a-40c4-8c7b-45050aef5b90"
+pub_id = "https://trustgraph.ai/pubev/59012ae1-65d4-441f-8288-b6f3c6c15333"
+
+# Organization metadata
+org_facts = [
+    [org_id, "http://www.w3.org/1999/02/22-rdf-syntax-ns#type",
+     "https://schema.org/Organization"],
+    [org_id, "http://www.w3.org/2000/01/rdf-schema#label", "NASA"],
+    [org_id, "https://schema.org/name", "NASA"]
+]
+
+# Publication metadata.  Note how it links to the Organization
+pub_facts = [
+    [pub_id, "http://www.w3.org/1999/02/22-rdf-syntax-ns#type",
+     "https://schema.org/PublicationEvent"],
+    [pub_id, "https://schema.org/description", "Uploading to Github"],
+    [pub_id, "https://schema.org/endDate", "1986-06-06"],
+    [pub_id, "https://schema.org/publishedBy", org_id],
+    [pub_id, "https://schema.org/startDate", "1986-06-06"]
+]
+
+# Document metadata.  Note how it links to the publication event
+doc_facts = [
+    [doc_id, "http://www.w3.org/1999/02/22-rdf-syntax-ns#type",
+     "https://schema.org/DigitalDocument"],
+    [doc_id, "http://www.w3.org/2000/01/rdf-schema#label",
+     "Challenger Report Volume 1"],
+    [doc_id, "https://schema.org/copyrightHolder", "US Government"],
+    [doc_id, "https://schema.org/copyrightNotice",
+     "Work of the US Gov. Public Use Permitted"],
+    [doc_id, "https://schema.org/copyrightYear", "1986"],
+    [doc_id, "https://schema.org/description",
+     "The findings of the Presidential Commission regarding the circumstances surrounding the Challenger accident are reported and recommendations for corrective action are outlined"
+     ],
+    [doc_id, "https://schema.org/keywords", "nasa"],
+    [doc_id, "https://schema.org/keywords", "challenger"],
+    [doc_id, "https://schema.org/keywords", "space-shuttle"],
+    [doc_id, "https://schema.org/keywords", "shuttle"],
+    [doc_id, "https://schema.org/keywords", "orbiter"],
+    [doc_id, "https://schema.org/name", "Challenger Report Volume 1"],
+    [doc_id, "https://schema.org/publication", pub_id],
+    [doc_id, "https://schema.org/url",
+     "https://ntrs.nasa.gov/citations/19860015255"]
+]
+
+def to_value(x):
+    if x.startswith("https://"):
+        return { "v": x, "e": True }
+    if x.startswith("http://"):
+        return { "v": x, "e": True }
+    return { "v": x, "e": False }
+
+# Convert the above metadata into the right form
+metadata = [
+    { "s": to_value(t[0]), "p": to_value(t[1]), "o": to_value(t[2]) }
+    for t in org_facts + pub_facts + doc_facts
+]
+
+input = {
+    
+    # Document identifer.  Knowledge derived by TrustGraph is linked to this
+    # identifier, so the additional metadata specified above is linked to the
+    # derived knowledge and users of the knowledge graph could see
+    # information about the source of knowledge
+    "id": doc_id,
+    
+    # Additional metadata in the form of RDF triples
+    "metadata": metadata,
+    
+    # Text character set.  Default is UTF-8
+    "charset": "utf-8",
+    
+    # The PDF document, is presented as a base64 encoded document.
+    "data": base64.b64encode(text).decode("utf-8")
+
+}
+
+resp = requests.post(
+    f"{url}load/document",
+    json=input,
+)
+
+resp = resp.json()
+
+if "error" in resp:
+    print(f"Error: {resp['error']}")
+    sys.exit(1)
+
+print(resp)
+