code: @Override
      public void visit(Collection<? extends PropositionDefinition> propositionDefinitions)
              throws ProtempaException {
          for (PropositionDefinition def : propositionDefinitions) {
              def.acceptChecked(this);
          }
      }
docs: Processes a collection of proposition definitions.
  
  @param propositionDefinitions
  a {@link Collection<PropositionDefinition>}.
  @throws ProtempaException
  if an error occurs.
  
  @see org.protempa.PropositionDefinitionCheckedVisitor#visit(java.util.Collection)