async complete(messages, functions = []) {
    try {
      let completion;
      if (functions.length > 0) {
        const { toolCall, text } = await this.functionCall(
          messages,
          functions,
          this.#handleFunctionCallChat.bind(this)
        );

        if (toolCall !== null) {
          this.providerLog(`Valid tool call found - running ${toolCall.name}.`);
          this.deduplicator.trackRun(toolCall.name, toolCall.arguments);
          return {
            result: null,
            functionCall: {
              name: toolCall.name,
              arguments: toolCall.arguments,
            },
            cost: 0,
          };
        }
        completion = { content: text };
      }

      if (!completion?.content) {
        this.providerLog(
          "Will assume chat completion without tool call inputs."
        );
        const response = await this.client.chat.completions.create({
          model: this.model,
          messages: this.cleanMsgs(messages),
        });
        completion = response.choices[0].message;
      }

      // The UnTooled class inherited Deduplicator is mostly useful to prevent the agent
      // from calling the exact same function over and over in a loop within a single chat exchange
      // _but_ we should enable it to call previously used tools in a new chat interaction.
      this.deduplicator.reset("runs");
      return {
        result: completion.content,
        cost: 0,
      };
    } catch (error) {
      throw error;
    }
  }
Create a completion based on the received messages.

@param messages A list of messages to send to the API.
@param functions
@returns The completion.