func NewHTTPClient(spClient *gosip.SPClient) *HTTPClient {
	return &HTTPClient{sp: spClient}
}
NewHTTPClient creates an instance of httpClient
package api
import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"strings"
	"github.com/koltyakov/gosip"
)
type HTTPClient struct {
	sp *gosip.SPClient
}
type RequestConfig struct {
	Headers map[string]string
	Context context.Context
}
var HeadersPresets = struct {
	Verbose         *RequestConfig
	Minimalmetadata *RequestConfig
	Nometadata      *RequestConfig
}{
	Verbose: &RequestConfig{
		Headers: map[string]string{
			"Accept":          "application/json;odata=verbose",
			"Content-Type":    "application/json;odata=verbose;charset=utf-8",
			"Accept-Language": "en-US,en;q=0.9",
		},
	},
	Minimalmetadata: &RequestConfig{
		Headers: map[string]string{
			"Accept":          "application/json;odata=minimalmetadata",
			"Content-Type":    "application/json;odata=verbose;charset=utf-8",
			"Accept-Language": "en-US,en;q=0.9",
		},
	},
	Nometadata: &RequestConfig{
		Headers: map[string]string{
			"Accept":          "application/json;odata=nometadata",
			"Content-Type":    "application/json;odata=verbose;charset=utf-8",
			"Accept-Language": "en-US,en;q=0.9",
		},
	},
}