code: protected void beginToCompile(ICompilationUnit[] sourceUnits) {
          int maxUnits = sourceUnits.length;
          this.totalUnits = 0;
          this.unitsToProcess = new CompilationUnitDeclaration[maxUnits];
  
          internalBeginToCompile(sourceUnits, maxUnits);
      }
docs: Add the initial set of compilation units into the loop
  ->  build compilation unit declarations, their bindings and record their results.