system/Database/SQLite3/Table.php
public function modifyColumn(array $field)
	{
		$field = $field[0];

		$oldName = $field['name'];
		unset($field['name']);

		$this->fields[$oldName] = $field;

		return $this;
	}
public function modifyColumn(array $field)
	{
		$field = $field[0];

		$oldName = $field['name'];
		unset($field['name']);

		$this->fields[$oldName] = $field;

		return $this;
	}
Modifies a field, including changing data type,
renaming, etc.

@param array $field

@return \CodeIgniter\Database\SQLite3\Table