Show warning in case the base unit is missing from a node

dsiParser.py

@@ -50,6 +50,9 @@ def _nodeToLatex(node: list):
         latexString += r'{\color{red}\mathrm{'+node[1]+r'}}'
     if node[2]:
         latexString += r'^' + node[2]
+    
+    if node[1] == "":
+        latexString = r'{\color{red}'+latexString+r'}'
     return latexString
 
 def _parseDsi(dsiString: str):
@@ -139,6 +142,13 @@ def _parseFractionlessDsi(dsiString:str):
             except IndexError:
                 item = ''
             warnings.warn(f"The identifier \"{tuple[1]}\" does not match any D-SI units!", RuntimeWarning)
+        elif tuple[1] == '':
+            itemStr = ""
+            if tuple[0] != "":
+                itemStr = itemStr + "\\" + tuple[0]
+            if tuple[2] != "":
+                itemStr = itemStr + r"\tothe{" + tuple[2] + r"}"
+            warnings.warn(f"This unit seems to be missing the base unit! \"{itemStr}\"", RuntimeWarning)
 
         nodes.append(tuple)
         if len(items) == 0: break