bool has_tpu = false;
  for (int device_index = 0; device_index < TF_DeviceListCount(devices.get());
       ++device_index) {
    std::string device_type =
        TF_DeviceListType(devices.get(), device_index, status.get());
    ASSERT_EQ(TF_GetCode(status.get()), TF_OK) << TF_Message(status.get());
    if (device_type == "TPU") {
      has_tpu = true;
      break;
    }
  }

func hasPolymorphicRelation(tagSettings map[string]string) bool {
	if _, ok := tagSettings["POLYMORPHIC"]; ok {
		return true
	}

	_, hasType := tagSettings["POLYMORPHICTYPE"]
	_, hasId := tagSettings["POLYMORPHICID"]

	return hasType && hasId
}

func (schema *Schema) setRelation(relation *Relationship) {
	// set non-embedded relation

	ExprArg *Expression `parser:" @@? )! \")\""`
}

// CastFunc represents CAST sql function
type CastFunc struct {
	Expr     *Expression `parser:" \"CAST\" \"(\" @@ "`
	CastType string      `parser:" \"AS\" @(\"BOOL\" | \"INT\" | \"INTEGER\" | \"STRING\" | \"FLOAT\" | \"DECIMAL\" | \"NUMERIC\" | \"TIMESTAMP\") \")\" "`
}

// SubstringFunc represents SUBSTRING sql function
type SubstringFunc struct {

type, called the <i>base type</i> of the pointer.
The value of an uninitialized pointer is <code>nil</code>.
</p>

<pre class="ebnf">
PointerType = "*" BaseType .
BaseType    = Type .
</pre>

<pre>
*Point
*[4]int
</pre>

<h3 id="Function_types">Function types</h3>

<p>
A function type denotes the set of all functions with the same parameter

type, called the <i>base type</i> of the pointer.
The value of an uninitialized pointer is <code>nil</code>.
</p>

<pre class="ebnf">
PointerType = "*" BaseType .
BaseType    = Type .
</pre>

<pre>
*Point
*[4]int
</pre>

<h3 id="Function_types">Function types</h3>

<p>
A function type denotes the set of all functions with the same parameter