code: def process_increase_expression_amount(self):
          
          statements = []
  
          pwcs = self.find_event_parent_with_event_child(
                  'Positive_regulation', 'Gene_expression')
          for pair in pwcs:
              pos_reg = pair[0]
              expression = pair[1]
  
              cause = self.get_entity_text_for_relation(pos_reg, 'Cause')
              target = self.get_entity_text_for_relation(expression, 'Theme')
  
              if cause is not None and target is not None:
                  theme_node = self.get_related_node(expression, 'Theme')
                  assert(theme_node is not None)
                  evidence = self.node_to_evidence(theme_node, is_direct=False)
  
                  statements.append(IncreaseAmount(s2a(cause), s2a(target),
                                    evidence=evidence))
          return statements
docs: Looks for Positive_Regulation events with a specified Cause
          and a Gene_Expression theme, and processes them into INDRA statements.